GIFT OF
Mars ton Campbell, Jr
THE
GAS AND OIL ENGINE
THE
GAS AND OIL ENGINE
BY
DUGALD CLERK
MEMBER OF THE INSTITUTION OF CIVIL ENGINEERS
FELLOW OF THE CHEMICAL SOCIETY : MEMBER OF THE ROYAL INSTITUTION
FELLOW OF THE INSTITUTE OF PATENT A.GENTS
NEW IMPRESSION (1904>
RE-FSSUE
JOHN WILEY & SONS
43 & 45 EAST NINETEENTH STREET
NEW YORK
1907
GIFT OF
BIBLIOGRAPHICAL NOTE.
First printed September 1886; Reprinted July
1887; June 1890; April 1891; January 1893;
October 1894. Revised and Enlarged June 1896 ;
Reprinted February 1897 ; Revised Edition November
1899; Reprinted January 1902; August 1904.
PREFACE
10
THE SIXTH EDITION.
MANY important changes have been made in the constructive
details of gas engines since the first part of this work was pub-
lished, and oil engines using heavy oil have become practicable
.motors, so that it has become necessary to bring the informa-
tion in this book thoroughly up to date. In doing this the author
thought it better to make additions rather than alterations on the
original, and accordingly the first part of the book is retained in
its original form, and two parts have been added : the second
part deals with modern gas engines, both impulse-every-revolution
and Otto cycle ; and the third part deals with the oil engine. The
first part of the book thus remains in the form in which it is
familiar to many engineers ; indeed, the author may say with truth
all engineers interested in the gas engine throughout the world,
because the book has been translated and published in German,
and many parts extracted in French works, while it is largely used
in America both by engineers and in the engineering classes of
the Universities.
In dealing with the various engines the author has drawn
upon his personal experience of gas and oil engines, now extending
832761
vi The Gas Engine
over twenty years, and he has endeavoured to discuss the various
points involved in a dispassionate manner, pointing out to the
engineer the difficulties as well as the advantages peculiar to each
construction or type. This is very necessary if moderately rapid,
advance is to be made, and it appears to the author most un-
desirable to adopt the tone so often found in engineering literature
of indiscriminate admiration of this or that firm's wonderful motor,
when in reality the motor discussed in so far as it departs from
standard practice is not an improvement, but the reverse. The
author has accordingly freely criticised any points which appear
to him defective in the various engines.
In this edition special attention has been paid to the oil
engine, in view of its rapid rate of present development and the
probability of its very extensive use for many new purposes, such
as motor cars. Many engineers are now paying attention to the
oil engine, to whom the subject is unfamiliar ; and in the hope of
proving useful to such new men on the work, the author has gone
carefully into the discussion of the chemical nature of petroleum
and the different methods of vaporising heavy oils.
In dealing with the oil engine the author has freely availed
himself of the careful experiments on oil engines by the engineers
for the Royal Agricultural Society's Show at the Cambridge
Meeting. The author has made many tests himself ; but as these
were mostly made in the course of his professional work and were
confidential, he has chosen for discussion the publicly made tests
and descriptions rather than his personal tests.
In concluding, the author expresses his thanks to the Council
of the Institution of Civil Engineers for the use of illustrations
from papers by Professor Unwin and Mr. J. E. Dowson, published
in the valuable Minutes of the Institution, and also for extracts of
Preface to the Sixth Edition vii
tests by Mr. Dowson, and tables by the author, also published in
Institution papers.
The author also thanks the various makers of gas and oil
engines who have allowed him to test their engines for the
purposes of this book, and who have lent him blocks ; among those
makers are Messrs. Crossley Bros. Limited, J. E. H. Andrew
& Co. Limited, T. B. Barker & Co., Tangyes, Limited, Robey
& Co. Limited, Wells Bros., Hornsby & Sons, Fielding & Platt,
Mr. Peter Burt, and Mr. Bellamy of Andrew & Co.
Many of the drawings for the book, however, have been made
by the author's draughtsmen directly from the engines.
In the Appendix the author has added a complete list of
British gas and oil engine patents from 1791 to the end of 1893.
All the English specifications from 1876, including this year, are
in the author's possession, and he will be very pleased to freely
allow those interested access to them.
D. a
18 SOUTHAMPTON BUILDINGS, CHANCERY LANE,
LONDON : June 1896.
PREFACE
TO
THE FIRST EDITION.
IN this work the author has endeavoured to systematise the know-
ledge in existence upon the subject, and to explain the science
and practice of the Gas Engine in a way which he hopes may be
useful to the engineer.
The historical sketch with which the book opens proves that,
like other great subjects, the gas engine has long occupied men's
minds.
The first six chapters treat of theory, including the distin-
guishing features of the gas engine method, classification, thermo-
dynamics of the various types, and the chemical and physical
phenomena of combustion and explosion.
In the seventh chapter, standard engines illustrative of the
different types are described, and tests from each engine for power
and consumption of gas are given. The diagrams and efficiencies
are shortly discussed, compared with theory, and the various sources
of loss pointed out.
The eighth chapter deals with typical igniting arrangements,
and the ninth with governing gear and other mechanical details.
x Preface to the First Edition
The tenth chapter briefly describes and discusses various
theories which have been propounded concerning the action of
the gases in the cylinder of the gas engine and in gaseous explo-
sions.
In the last chapter the great sources of loss of heat still
existing in the best gas engines are discussed, with the object of
pointing out the way still open for further advance.
Many of the tests and most of the theoretical and practical
discussion, result from the author's personal experience with the
gas engine.
In the chapter on thermodynamics the author is much indebted
to the work of the late Prof. RANKINE, and he has adopted, in
treating of efficiency, some of the elegant formulae of Dr. AIME
WITZ, of Lille, to whom as well as to Prof. SCHOTTLER and Prof.
THURSTON he has much pleasure in expressing his indebtedness.
D. C.
BIRMINGHAM : July 1886.
CONTENTS.
PART I.
THE GAS ENGINE UP TO THE YEAR 1886.
•CHAPTER PAGE
HISTORICAL SKETCH OF THE GAS ENGINE, 1690 TO 1886 . i
I. THE GAS ENGINE METHOD . . . . . . . 23
II. GAS ENGINES CLASSIFIED 29
III. THERMODYNAMICS OF THE GAS ENGINE . . . . 36
IV. THE CAUSES OF Loss IN GAS ENGINES .... 72
V. COMBUSTION AND EXPLOSION . . . . . . 79
VI. EXPLOSION IN A CLOSED VESSEL 95
VII. THE GAS ENGINES OF THE DIFFERENT TYPES IN PRACTICE 116
VIII. IGNITING ARRANGEMENTS . . ;. . . P . •. 202
IX. ON SOME OTHER MECHANICAL DETAILS . . . . 226
X. THEORIES OF THE ACTION OF THE GASES IN THE GAS
ENGINE . . . . . . . . ^:* . . 243
XL THE FUTURE OF THE GAS ENGINE . > . . . 260
PART II.
GAS ENGINES PRODUCED SINCE 1886.
I. GAS ENGINES GIVING AN IMPULSE FOR EVERY REVOLUTION 271
II. OTTO CYCLE GAS ENGINES 297
xii The Gas Engine
CHAPTER PAGE
III. THE PRODUCTION OF GAS FOR MOTIVE POWER . . 354
IV. THE PRESENT POSITION OF GAS ENGINE ECONOMY . . 375
PART III.
OIL ENGINES.
I. PETROLEUM AND PARAFFIN OILS 387
II. OIL ENGINES 407
III. THE DIFFICULTIES OF OIL ENGINES 462
APPENDIX I.
ADIABATIC AND ISOTHERMAL COMPRESSION OF DRY AIR . . . 475
VARIOUS ANALYSES OF COAL GAS 476
APPENDIX II.
COMPOSITION OF COAL AND CANNEL GASES (FRANKLAND) . . 478-
DATA CALCULATED FROM FRANKLAND'S ANALYSIS . . . . 479
OXYGEN REQUIRED FOR COMPLETE COMBUSTION OF THE GASES
GIVEN IN FRANKLAND'S ANALYSIS 480-
LIST OF BRITISH GAS AND OIL ENGINE PATENTS FROM 1791 TO
1897 INCLUSIVE . . 481
NAME INDEX TO GAS AND OIL ENGINE PATENTS. . . . 558-
GENERAL INDEX . . 575
THE
GAS ENGINE.
HISTORICAL SKETCH OF THE GAS ENGINE.
THE origin of the gas engine is but imperfectly known ; by some
it is dated as far back as 1680, when Huyghens proposed to use
gunpowder for obtaining motive power. Papir^ i^i 16.99,, continued i
Huyghens' experiments, but without success, v^d'nieihbd us^c} J*
was a fairly practicable one. The explosiqri -was used ^djre.qtly ;
a small quantity of gunpowder exploded in ^largec^iiciilealfyeSsfel \ '
rilled with air, expelled the air through check valves, thus leaving,
after cooling, a partial vacuum. The pressure of the atmosphere
then drove a piston down to the bottom of the vessel, lifting a
weight or doing other work.
In a paper, published at Leipsic in 1688, Papin stated that,
* until now all experiments have been unsuccessful ; and after the
combustion of the exploded powder, there always remains in the
cylinder about one-fifth of its volume of air.'
The Abbe Hautefeuille made similar proposals, but does not
seem to have made actual experiments. These early engines
cannot be classed as gas engines. The explosion of gunpowder is
so different in its nature from that of a gaseous mixture that com-
parison is untenable. The first real gas engine described in this
country is in Robert Street's patent, No. 1983, 1794. It contains a
motor cylinder in which works a piston connected to a lever,
from which lever a pump is driven. The bottom of the motor
cylinder is heated by a fire ; a few drops of spirits of turpentine
2 The Gas Engine
being introduced and evaporated by the heat, the motor piston
is drawn up, and air entering mixes with the inflammable vapour,
the application of a flame to a touch-hole causing explosion ; and
the piston being driven up forces the pump piston down, so per-
forming work in raising water. The details, as described, are
crude, but the main idea is correct and was not improved upon in
practice till very lately.
Samuel Brown's inventions come next. His patents are dated
1823 and 1826, Nos. 4874 and 5350. The principle used is in-
A, Cover raised, vessel filling with flame. .B and C, Covers down, vessels vacuous.
FIG. I. — Brown's Gas- vacuum Engine, 1826.
genious, and easily carried out in practice, but it is not economical,
and it gives a very cumbrous machine for the amount of power
produced. A partial vacuum is produced by filling a vessel with
flame, and expelling the air it contains, a jet of water is thrown
in and condenses the flame, giving vacuum. The atmospheric
pressure thus made available for power is utilised in any engine of
ordinary construction.
Brown's apparatus consists essentially of a large upright cylin-
Historical Sketch of the Gas Engine 3
drical vessel fitted on the top with a movable valve cover, of the
whole diameter of the cylinder. The cover is raised and lowered
from and to its seat by a lever and suitable gear at proper times.
The gas supply pipe enters the cylinder at the bottom ; the
cylinder being filled with air, and the valve raised, the gas
cock is opened and the issuing gas lighted by a small flame
as it enters the cylinder. The flame produced fills the whole
vessel, expelling the air it contains ; the valve being now
lowered and the gas supply shut off, the water-jet is thrown in
and causes condensation. To keep up a constant supply of power,
several of these cylinders are required, so that one at least may be
always vacuous while the others are in the process of obtaining
the vacuum. In the specification three are shown and three
engines. The engines are all connected to the same crank-shaft.
Notwithstanding this provision, the motion . must have been
irregular. The idea was evidently suggested by the condensing
steam engine ; instead of using steam to obtain a vacuum flame is
employed. Brown's engine, although uninteresting theoretically,
is important as being the first gas engine undoubtedly at work.
According to the ' Mechanics' Magazine,' published in London, a
boat was fitted with one including a complete gas generating
plant, and was run upon the Thames not for public use but only
as an experiment. Another engine was made in combination
with a road carriage ; it also ran in London. If these statements
are to be relied upon, then Samuel Brown was a really great man
and should be considered as the Newcomen of the gas engine ; in
some points he achieved a measure of success not yet equalled by
his successors.
W. L. Wright, 1833, No. 6525. — In this specification the
drawings are very complete and the details are carefully worked
out. The explosion of a mixture of inflammable gas and air acts
directly upon the piston, which acts through a connecting rod upon
a crank-shaft. The engine is double-acting, the piston receiving
two impulses for every revolution of the crank-shaft. In appear-
ance it resembles a high pressure steam engine of the kind known
as the table pattern. The gas and air are supplied to the motor
cylinder from separate pumps through two reservoirs, at a pressure
a few pounds above atmosphere, the gases (gas and air) enter
• B 2
4 The Gas Engine
spherical spaces at the ends of the motor cylinder, partly displacing
the previous contents, and are ignited while the piston is crossing
the dead centre. The explosion pushes the piston up or down
through its whole stroke ; at the end of the stroke the exhaust
valve opens and the products of combustion are discharged during
FIG. 2.— Wright's Gas-exploding Engine, 1833.
the return, excepting the portion remaining in the spaces not
entered by the piston. The ignition is managed by an external
flame and touch-hole. The author has been unable to find
whether the engine was ever made, but the knowledge of the
detail essential to a working gas engine shown by the drawings
indicates that it or some similar machine had been worked by the
Historical Sketch of the Gas Engine 5
inventor. Both cylinder and piston are water-jacketed, as would
have been necessary in a double-acting gas engine to preserve the
working parts from damage from the intense heat of the explosion.
This is the earliest drawing in which this detail is properly shown.
William Barnett ^ 1838, No. 7615. — Barnett's inventions as
described in his specification are so important that they require
more complete description than has been here accorded to earlier
inventors.
Barnett is the inventor of a very good form of igniting arrange-
ment. The flame method most widely used at the present time
was originated by him.
Barnett is also the inventor of the compression system now so
largely used in gas engines. The Frenchman, Lebon, it is true,
described an engine using compression, in the year 1801, but his
cycle is not in any way similar to that proposed by Barnett, or
used in the modern gas engine. Barnett describes three engines.
The first is single-acting, the second and third are double-acting ;
all compress the explosive mixture before igniting it. In the first
and second engines the inflammable gas and air is compressed by
pumps into receivers separate from the motor cylinder, but com-
municating with it by a short port which is controlled by a piston
valve. The piston valve also serves to open communication
between the cylinder and the air when the motor piston dis-
charges the exhaust gases.
In the third engine the explosive mixture is introduced into
the motor cylinder by pumps, displacing as it enters the exhaust
gases resulting from the previous explosion ; the motor piston by
its ascent or descent compresses the mixture. Part of the com-
pression is accomplished by the charging pumps, but it is always
completed in the motor cylinder itself.
In all three engines the ignition takes place when the crank is
crossing the dead centre, so that the piston gets the impulse during
the whole forward stroke.
Fig. 3 is a sectional elevation of the first engine, showing the
principal working parts, but omitting all detail not required for
explaining the action.
There are three cylinders containing pistons ; A is the motor
piston, B is the air pump piston. The gas pump piston cannot be
6 The Gas Engine
seen in the section, but works 'in the same crosshead as B. The
motor piston is suitably connected to the crank shaft, and the
other two are also connected by levers in such manner that all
three move simultaneously up or down. The pump pistons,
moving up, take respectively air and inflammable gas into their
FIG. 3.— Barnett Gas Engine.
cylinders ; upon the down stroke the gases are forced through an
automatic lift valve into the receiver D, and there mix. When the
down stroke is complete and the receiver is fully charged with the
explosive mixture, the pressure has risen to about 25 Ibs. per square
inch above atmosphere. At the same time as the pumps are com-
pressing, the motor piston is moving down and discharging the
Historical Sketch of the Gas Engine 7
exhaust gases from the power cylin'der ; it reaches the bottom of
its stroke just when compression is complete. The piston valve
E then opens communication between the receiver and the motor,
at the same time closing to atmosphere. The motor cylinder
being in free communication with the receiver, the explosion of
the mixture is accomplished by the igniting cock or valve F ; the
pressure resulting actuates the motor piston during its whole up-
FIG, 4 — Barnett's Igniting Cock.
ward stroke, the hot gases flowing through the port G precisely as
steam would do. The volume of the receiver being constant, the
pressure in the motor cylinder slowly falls by expansion, due to
the movement of the piston, upon which work is performed, and
by cooling, the pressure still existing in the cylinder when the
stroke is complete depending on the ratio between the volume
swept by the motor piston and the volume of the receiver.
8 The Gas Engine
The down stroke again expels the products of combustion, the
valve opening to atmosphere, while the compression again takes
place. This cycle gives a single-acting engine. It is obvious that as
the piston A does not enter the receiver it cannot displace the
exhaust gases there. If means are not taken to expel these gases
they must mix with the fresh explosive charge pumped in.
It is very desirable that these gases should be as completely
as possible discharged. An exhausting pump is described for
doing this, but in small engines it adds an additional complication ;
and so Barnett states that in some cases it may be omitted. The
exhaust gases do not so injuriously affect the action of small gas
engines.
The igniting valve is very ingenious. It is shown at Fig. 4, on a
larger scale. A hollow conical plug A is accurately ground into
the shell B, and is kept in position by the gland c ; the shell has
two long slits D and E ; the plug has one port so cut that as the
plug moves it shuts to the slit D before opening to E. In the
bottom of the shell there is screwed a cover carrying a gas burner
F, which may be lit while the port in the plug is open to the air
through D. The external constant flame H lights it. So long
as the plug remains in this position the internal flame continues
to burn quietly. If the plug be now turned to shut to the outer
air, it opens to the slit E, and as that contains explosive mixture
it at once ignites. The explosion extinguishes the internal flame,
but it is again lighted at the proper time when the plug is moved
round. The valve acts well and is almost identical in principle
with the flame-igniting arrangements of Hugon, Otto and Langen
and Otto.
Barnett's second engine is identical with his first except that
it is double-acting, and therefore requires a greater number of
parts.
Barnett's third engine is worthy of careful description. Fig. 5
is a vertical section of the principal parts. It is double-acting.
It has three cylinders, motor, air-pump and gas-pump ; the air
and gas pumps are single-acting, the motor piston is double-
acting. The pumps are driven from a separate shaft, which is
actuated from the main crank shaft by toothed wheels ; the wheel
upon the pump shaft is half the diameter of that on the motor
Historical Sketch of the Gas Engine 9
shaft, so that it makes two revolutions for one of the other. The
pumps therefore make one up-and-down stroke for each up or
down stroke of the motor piston ; the angles of the cranks are so
set that they (pumps) discharge their contents into one or other side
of the motor cylinder at every stroke ; the exhaust gases are partly
FIG. 5. — Barnett Engine.
displaced by the fresh explosive mixture, and the motor piston com-
pletes the compression in the motor cylinder itself. When full up
or down the igniting cock acts, and the explosion drives the piston
to the middle of its stroke ; it here runs over a port in the middle
of the cylinder, and the pressure at once falls to atmosphere.
io The Gas Engine
A is the motor piston ; B is the air-pump piston ; c is the gas-
pump piston, which is behind the air-pump, and therefore not
seen in the section ; D is the main crank shaft ; E the pump shaft
driven from the main shaft by the wheels F and G. The engine
is exceedingly interesting as the first in which the compression is
accomplished in the motor cylinder, but it is not so good a machine
as the first because of the difficulty of obtaining a sufficient amount
of expansion.
From 1838 to 1854 inclusive eleven British patents were applied
for ; some were not completed but only reached the provisional
stage. Of these patents by far the most important is Barnett's ; the
others are interesting as showing the gradual increase of attention
the subject attracted. The other names are Ador, 1838 ; Johnson,
1841 ; Robinson, 1843 ; Reynolds, 1844 ; Brown, 1846 ; Roger,
1853, also Bolton and Webb, making three patents for the year ;
for 1854 two patents, Edington and Barsanti and Matteucci. None
of the proposals in these patents are really valuable or novel,
being anticipated by either Street, Wright, or Samuel Brown.
Robinson's is the best, being similar to Lenoir's in some of its
details, and showing distinctly a better understanding of gas
engine detail.
A. V. Newton, 1855, N°- 562- — This specification is interesting,
and describes for the first time a form of igniting arrangement
only now coming into use ; it seems to be identical with the
invention of the American Drake, although not described as a
communication from him. It is a double-acting engine, and takes
into the cylinder a charge of gas and air mixed, during a portion
of the stroke, at atmospheric pressure. The igniting arrangement
is a thimble-shaped piece of hard cast-iron which projects into a
recess formed in the side of the cylinder ; it is hollow, and is kept
at all times red-hot by a blow-pipe flame projected into it by a small
pump. When the piston uncovers the recess the explosive gases
coming in contact with it ignite, and the pressure produced drives
it forward.
.This is the first instance of ignition by contact with red-hot
metal ; the proposal has often been made since then in varying
forms.
Barsanti and Matteucci, 1857, No. 1655. — This is the first free
Historical Sketch of the Gas Engine 1 1
piston engine ever proposed ; instead of allowing the explosion to act
directly upon the motive power shaft through a connecting rod,
at the moment of explosion the piston is perfectly free. The
cylinder is very long, and is placed vertically. When the explosion
occurs, it expends its power in giving the piston velocity ; the
expansion therefore takes place with considerable rapidity, and
the piston, gaining speed until the pressure upon it falls to atmo-
sphere, moves on, till the energy of motion is absorbed doing work
on the external air, lifting the piston and in friction. When the
energy is all absorbed in this manner it stops ; it has reached the
top of its stroke. A partial vacuum has been formed in the cylinder,
and the weight has been raised through the stroke. It now
returns under the pressure of the atmosphere and its own weight ;
in returning, a rack attached to the piston engages the motive shaft
and drives it. The cooling of the gases as the piston descends
continues and helps to keep up the vacuum.
The method although indirect is economical. Three advantages
are gained by it — rapid expansion, considerable expansion (an ex-
pansion of six times is common in these engines), and also some
of the advantages of a condenser.
Fig. 6 shows a vertical section of their best modification. The
motor piston A working in the tall vertical cylinder B is attached to
the rack c, which works into the toothed wheel D. The motor
shaft E revolves in the direction of the arrow, and it is provided
with a ratchet ; a pall upon the wheel D engages the ratchet on the
down stroke of the piston only, on the up stroke it slips freely
past the ratchet. The piston A is therefore quite free to move
without the shaft on the up stroke, but it engages on the down
stroke. The cams F and G are arranged to strike projections
upon the rack, and so raise or lower the piston. It is raised when
the charge is to be taken in, and lowered when it has completed
its working stroke and the exhaust gases have to be discharged.
When raised the valve H is in the position shown. Air first enters
the cylinder through the port i, which also serves to discharge the
exhaust. After the piston has uncovered the port K the valve H
shuts on i, opening at the same time on K ; the gas supply then
enters and mixes more or less perfectly with the air previously
introduced.
12 The Gas Engine
A small further movement of the piston now closes the valve,
and the explosion is caused by the passage of the electric spark in
the position indicated upon the drawing. The piston shoots up
FIG. 6.— Barsanti and Matteucci Engine, 1857.
freely to the top of its stroke, to give out the work stored up usefully
upon its return.
As the next engine to be described marks the beginning of the
Historical Sketch of tJie Gas Engine 1 3
practicable stage of gas engine development, it is advisable to
summarise before proceeding.
Previous to 1860 the gas engine was entirely in the experimental
stage. Many attempts were made, but none of the inventors
sufficiently overcame the practical difficulties to make any of their
engines commercially successful. This was mostly due to the
very serious nature of the difficulties themselves, but it was also
due to too great ambition of the inventors ; they wished not only
to compete with the steam engine for small powers, but for large
powers. They thought in fact more to displace the steam engine
than to compete with it.
This is clearly shown in many of their descriptions of the appli-
cations of their inventions.
The greatest credit is due to Wright and Barnett. Wright
very closely proposed the modern non-compression system, Barnett
the modern compression system. Barnett is also the originator of
one of the modern flame systems for ignition. Barsanti and
Matteucci follow in order of merit as the inventors of the free-piston
gas engine.
M. Lenoir occupies the honourable position of the inventor
of the first gas engine ever actually introduced to public use. The
engine was not strikingly novel ; nothing was done in it which had
not been proposed before, but its details were thoroughly and
carefully worked out. It was in fact the first to emerge from the
purely experimental stage. Lenoir's real credit consists in over-
coming the practical difficulties sufficiently to make previous
proposals fairly workable.
The principle is exceedingly simple and evident. The piston
moves forward for a portion of its stroke, by the energy stored in
the fly wheel, and takes into the cylinder a charge of gas and air
at the ordinary atmospheric pressure. The valves cut off com-
munication, and the explosion is occasioned by the electric spark ;
this propels the piston to the end of the stroke. Exhausting is
done precisely as in the steam engine.
The engine is simply an ordinary high-pressure steam engine with
valves arranged to admit gas and air and discharge the products
of combustion. Fig. 7 is an external elevation of a three-horse
engine. It was first constructed in Paris in 1860 by M. Hippolyte
The Gas Engine
Historical Sketch of the Gas Engine 1 5
Marinoni. In Moigno's ' Cosmos ' of that year it is stated that two
engines were in course of manufacture, one of six horse-power, the
other of twenty.
The early statements of its economy were ludicrously inaccurate.
A one horse-power engine consumed, it was said, but 3 cubic metres
(106 cubic ft. nearly) of coal gas in twelve hours' work, and therefore
cost for fuel not more than one-half of what a steam engine would
have done.
The actual consumption was speedily shown to be much nearer
3 cubic metres per effective horse-power per hour.
Notwithstanding the high consumption, the engine had many
good points ; its action was exceedingly smooth ; no shock whatever
was heard from the explosion. Indeed it is quite impossible when
watching the engine in motion to realise that regular explosions
are occurring. The motion is as smooth and silent as in the best
steam engines.
In the 'Practical Mechanics' Journal' of August 1865, there
is an article describing the progress made by the engine since the
date of its introduction, from which it appears that in Paris and
France from 300 to 400 engines were then at work, the power ranging
from half horse to three horse.
The Reading Iron Works .Company, Limited, at Reading, un-
dertook the manufacture for this country. One hundred engines
were made and delivered by them : several of them have continued
at work till now. Notably one engine inspected by the author at
Petworth House, Petworth, worked for twenty years pumping water,
and is even yet in good condition.
The work performed by the engines was multifarious in its
character — printing, pumping water, driving lathes, cutting chaff,
sawing stone, polishing marble, in fact, wherever from one-half to
three horse-power was sufficient.
Lenoir's patent in this country was obtained by J. H. Johnson,
1860, No. 335. It describes very closely the engine as manu-
factured both in France and England. The subsequent patent,
1 86 1, No. 107, does not seem to have been carried into effect.
These specifications contain many erroneous ideas, showing
the notions then prevalent among inventors of the nature of
gaseous explosions. Lenoir erroneously supposed that the economy
1 6 The Gas Engine
of his engine would be improved if he could obtain a slower
explosion. He evidently thought that the power imparted to the
piston by explosion was similar in nature to a sudden blow — a
rapid rise of pressure, and a fall nearly as rapid. He therefore
attempted to avoid explosion by such expedients as stratification
and injection of steam or water spray. The stratification idea he
very clearly expressed in his second specification, stating that ' the
object of preventing the admixture of air and gas is to avoid
explosion.' It is somewhat extraordinary to find notions so
erroneous common at a time when Bunsen's work had clearly
proved the continuous nature of the combustion in gaseous explo-
sions, and when Hirn had made experiments which showed that
the heat evolved by explosion in a gas engine was only a small
part of the total heat of the combustion, the heat which did not
appear during explosion being produced during expansion.
Other speculations on the cause of the uneconomical working
of the engine were frequent, but the true reason was fully explained
by Gustav Schmidt in a paper read before ' The Society of Ger-
man Engineers ' in 1 86 1. He states : 'The results would be far
more favourable if compression pumps, worked from the engine,
compressed the cold air and cold gas to three atmospheres before
entrance into the cylinder ; by this a greater expansion and trans-
formation of heat is possible.'
This opinion became common at this time. Compression
engines were proposed with great clearness and a full understand-
ing of the advantages to be gained.
Million^ 1 86 1, No. 1840. — This Frenchman had exceedingly
clear ideas of the advantages of compression ; he evidently con-
siders himself as the first to propose its use in a gas engine,
apparently unaware of the existence of Barnett's engine already
described. He claims the exclusive right to use compression in
the most emphatic language.
The first engine described is exactly what Schmidt asks for.
Separate pumps compress the air and gas into a reservoir, from
which the movement of the motor piston, during a portion of the
stroke, withdraws its charge under compression. Ignition is ac-
complished by the electric spark, and the piston moves forward
under the high pressure produced. He states :
Historical Sketch of the Gas Engine 1 7
" In ordinary air engines the operation of the motive cylinders
is analogous to that of the pumps, the result being that there are
two cylinders, which act in directions contrary to each other, and
that the pump, which is an organ of resistance, even works at a
greater pressure than that of the motive cylinder, which is an
organ of power. Thus these engines are very large in proportion to
their power. On the contrary by employing gases under the con-
ditions above explained, these engines will exert great power in
proportion to their dimensions. The sudden ignition of the gases
in the motive cylinder causes the latter to work at an operative
pressure much greater than that of the pumps.'
The advantage of compression in a gas engine could not be
more fully and clearly stated. But he goes even a step further ;
he sees that the portion of the motor piston stroke spent in taking
in the charge under compression, is a disadvantage, and he pro-
poses to make the whole stroke available for power by providing a
space at the end of the cylinder in which the gases are compressed.
'Instead of introducing the cold gases into the cylinders,
during a portion of the stroke and igniting them afterwards, when
the induction ceases . . . another arrangement might be adopted.
The motive cylinder might be made longer than necessary, in
order that the piston should always leave between it and the end
of the cylinder a greater or less space, according to the pleasure
of the constructor, such as one-fourth or one-third, more or less,
of the volume generated by the motive piston. This space is
called by the inventor a cartridge. On opening the slide valve
the gases could be allowed to enter suddenly from the pressure
reservoir into this cartridge towards the dead point, and this induc-
tion having ceased, an electric spark would ignite the gases in
the cartridge by which the driving piston would be set in motion.'
Such an engine would resemble in its action the best modern
compression engines. The difficulties of ignition however are too
considerable to be overcome without further detail
The compression idea at this date was evidently widely
spread, because it again crops up in a remarkably clever pamphlet
by M. Alph. Beau de Rochas, published at Paris in 1862. He
advances a step further than Million, and investigates the con-
ditions of greatest economy in gas engines using compression,
c
1 8 The Gas Engine
with reference to volume of hot gases and surfaces exposed. He
states that to obtain economy with an explosion engine, four con-
ditions are requisite :
1. The greatest possible cylinder volume with the least pos-
sible cooling surface.
2. The greatest possible rapidity of expansion.
3. The greatest possible expansion ; and
4. The greatest possible pressure at the commencement of the
expansion.
In using boiler tubes, he states, the efficiency of the heat
transmitted increases with reduction in the diameter of the tubes.
In the case of engine cylinders, therefore, the loss of heat of explo-
sion would be in inverse ratio to the diameter of the cylinders.
Therefore, he reasons, an arrangement which for a given con-
sumption of gas, gives cylinders of the greatest diameters, will
give the best economy, or least loss of heat to the cylinder. One
cylinder only must be employed in such an engine.
But loss of heat depends also upon time ; cooling, therefore,
will be proportionately greater as the working speed is slower.
The sole arrangement capable of combining these conditions, he
states, consists in using the largest possible cylinder, and reducing
the resistance of the gases to a minimum. This leads, he states,
to the following series of operations.
1. Suction during an entire outstroke of the piston.
2. Compression during the following instroke.
3. Ignition at the dead point and expansion during the third
stroke.
4. Forcing out of the burned gases from the cylinder on the
fourth and last return stroke.
The ignition he proposes to accomplish by the increase of
temperature due to compression. This he expects to do by
compressing to one- fourth of the original volume.
In our own country the late Sir C. W. Siemens proposed com-
pression in 1862. The idea was exceedingly widely spread, as is
evident from those numerous and independent inventions. The
practical experience to enable it to be successfully effected had
yet to be created, however, and this took many years of patient
work.
Historical Sketch of the Gas Engine 19
The igniting arrangement was the first weak point requiring
improvement. The electrical method of Lenoir was exceedingly
delicate and troublesome.
C2
2O The Gas Engine
Hugon's engine, produced in 1865, was similar to Lenoir's ;
but the igniting was accomplished by flame, a modification of
Barnett's, 1838, using a slide valve instead of a lighting cock.
The flame ignition was certain and easily kept in order. In
other points the engine was a great improvement upon its prede-
cessor. The lubrication was improved by injecting water into the
cylinder and the cooling water jacket was better arranged. As a
result the consumption of gas was reduced.
Fig. 8 is an external elevation of the Hugon engine.
Mr. Otto now appears upon the scene. Before him much had
been done in inventing and studying engines, but it remained for
him by sheer perseverance and determination of character, to
overcome all difficulties and reduce to successful practice the
theories of his predecessors.
In 1867 Messrs. Otto and Langen exhibited at the Paris exhibi-
tion of that year, their free piston engine, exterior elevation shown
at fig. 9. It was absolutely identical in principle with the previous
invention of Barsanti and Matteucci, but the details were com-
pletely and successfully carried out. The Germans succeeded
commercially and scientifically when the Italians completely
failed.
Flame ignition was used and great economy was obtained, a half-
horse engine, according to Professor Tresca, giving over half-horse
power effective, on a gas consumption at the rate of 44 cubic feet
.per effective horse- power per hour. This is less than half the
consumption of Lenoir or Hugon ; accordingly the prejudice ex-
cited by the strange appearance and noisy action of the engine
did not prevent its sale in large numbers. It completely crushed
Lenoir and Hugon, and held almost sole command of the market
for ten years, several thousands being constructed in that period.
The Brayton gas engine appeared in America in 1873, but
although more mechanical than any free piston engine, its economy
was insufficient to enable it to compete. It was better than Lenoir
or Hugon, but not nearly so good as Otto and Langen.
Other inventors attempted free piston engines, but with small
success.
In 1876 Mr. Otto superseded his former invention by the
production of the ' Otto Silent ' engine, now known all over the
Historical SketcJi of the Gas Engine
21
globe. It is a compression engine, using the precise cycle described
in 1862 by Beau de Rochas, but carried out in a most perfect
manner and using a good form of flame ignition, a modified Otto and
Langen valve in fact. The economy is greater than that of any
FIG. 9.— Otto and Langen Free Piston Engine.
previous engine, one indicated horse being obtained upon 20 cubic
feet of gas, or one effective horse upon 24 to 30 cubic feet per
hour.
This engine has established gas engines upon a firm commercial
basis, 15,000 having been sold since its invention ; this represents
at least an effective power of 90,000 horses.
22 The Gas Engine
Strangely enough, although Mr. Otto is the greatest and most
successful gas engine- inventor who has yet appeared, he adheres
to Lenoir's erroneous ideas, and in his specification 2081 of 1876
he attributes the economy of his machine to a slow explosion caused
by arrangement of gases within the cylinder.
The compression, which is the real cause of the economy and
efficiency of the machine, he seems to consider as an accidental and
unessential feature of his invention.
The gas engine, like all great inventions, is the result of the
long-continued labour of many minds ; it is a gradual growth due
to the united labours of many inventors. In the earlier days of
motive power, explosion was as much in the minds of the inventors,
Huyghens and Papin, as steam, but the mechanical difficulties
proved too great. The constructive skill of the time was heavily
taxed by the rude steam engine of Newcomen, and still more
unequal to the invention of James Watt ; it was in 1774 that Watt
ran his first successful steam engine at Soho Works, Birmingham.
Twenty years later, 1794, Street's gas engine patent indicated the
direction of men's minds, seeking a rival for steam before steam had
been completely introduced. The experience and skill accumulating
in the construction of the steam engine made the gas engine more
and more possible.
The proposals of Brown, 1823 ; Wright, 1833 ; Barnett, 1838 ;
Barsanti and Matteucci, 1857, show gradually increasing knowledge
of detail and the difficulties to be overcome, all leading to the first
practicable engine in 1860, the Lenoir.
Since that date till now, twenty-five years, great advances have
been made, and at present the gas engine is the only real rival to
steam.
CHAPTER I.
THE GAS ENGINE METHOD.
GAS ENGINES, while differing widely in theory of action and
mechanical construction, possess one feature in common which
distinguishes them from other heat engines : that feature is the
method of heating the working fluid.
The working fluid is atmospheric air, and the fuel required to
heat it is inflammable gas. In all gas engines yet produced, the
air and gas are mixed intimately with each other before introduc-
tion to the motive cylinder ; that is, the working fluid and the
fuel to supply it with heat are mixed with each other before the
combustion of the fuel.
The fuel, which, in the steam and in most hot-air engines, is
burned in a separate furnace, is, in the gas engine, introduced
directly to the motive cylinder and burned there. It is indeed
part of the working fluid.
This method of heating may be called the gas-engine method,
and from it arises at once the great advantages and also the great
difficulties of these motors.
Compare first with the steam engine. In it there exist two
great causes of loss : water is converted into steam, absorbing a
great amount of heat in passing from the liquid to the gaseous
state ; after it has been used in the engine it is rejected into the
atmosphere or the condenser, still existing as steam. The heat
necessary to convert it from the liquid to the gas is consequently
in most part rejected with it. Loss, occurring in this way, would
be small if high temperatures could be used ; but this is the point
where steam fails. High temperatures cannot be obtained without
pressure so great as to be quite unmanageable. The attempt to obtain
high temperatures by super-heating has often been made, but with-
24 The Gas Engine
out any substantial success. Although the difficulty of excessive
pressure is avoided, another set of troubles are introduced. All the
heat to be given to the gaseous steam must pass through the iron
plates forming the boiler or super-heater, which plates will only
stand a comparatively low temperature, certainly not exceed-
ing that of a low red heat, or about 600° to 700° C. Steam,
being a gas, is much more difficult to heat than water ; it follows
that even these temperatures cannot be attained without enormous
addition to the heating surface. The difficulties of making a
workable engine using high temperature steam are so great that
even so distinguished an engineer and physicist as the late Sir
C. W. Siemens failed in his attempts, which extended over many
years. It may be taken then that low temperature is the natural
and unavoidable accompaniment of the steam method, arising
from the necessary change of the physical state of the working
fluid, and the limited temperature which iron will safely bear.
The originators of the science of thermodynamics have long
taught that the maximum efficiency of a heat engine is obtained
when there is the maximum difference between the highest and
lowest temperatures of the working fluid. So long ago as 1854,
Professor Rankine read a paper before the British Association,
' On the means of realising the advantages of the Air Engine,' in
which he expresses his belief that such engines will be found to be
the most economical means of developing motive power by the
agency of heat. In this opinion he stood by no means alone.
Engineers so able as Stirling, Ericsson, and Siemens ; physicists
so distinguished as Dr. Joule, and Sir Wm. Thomson, devoted
much energy and study to their practice and theory. Notwith-
standing all their efforts, aided by a host of less able inventors,
the difficulties proved too formidable ; and although more than
thirty years have now passed since Rankine announced his belief,
the hot-air engine proper, has made no real advance. Similar
causes to those acting in the steam engine impose a limit here.
It is true the complication of changing physical state is avoided,
but the limited resistance of iron to heat acts as powerfully
as ever. Air is much more difficult to heat than water, and, there-
fore, requires a much larger surface per unit of heat absorbed.
In the larger hot-air engines, accordingly, the furnaces and heating
The Gas Engine Method 25
surfaces gave great trouble. Very low maximum temperatures
were attained in practice. In a Stirling engine giving out thirty-
seven brake horse-power, the maximum temperature was only
343° C. ; in the engines of the ship ' Ericsson,' the maximum was
only about 212° C., according to Rankine, the indicated power
being about 300 horses. These figures show that the heating
surfaces were insufficient, as in both cases the furnaces were pushed
to heat the metal to a good red. A method of internal firing was
proposed, first by Sir George Cayley and afterwards carried out
with some success by others ; the furnace was contained in a
completely closed vessel, and the air to be heated was forced
through it before passing to the motor cylinder. The plan gave
better results, but the temperature of 700° C. was still the limit, as
the strength of the iron reservoir had to be considered, and the
hot gases had to pass through valves. Wenham's engine, described
in a paper read before the Institution of Mechanical Engineers in
1873, is a good example of this class. In it the highest temperature
of the working fluid, as measured by a pyrometer, was 608° C. ;
higher temperatures could easily have been got but the safety of
the engine did not permit it. Professor Rankine in his work on
the steam engine has very fully discussed the disadvantages arising
from low maximum temperatures. He calculates that in a perfect
air engine without regenerator an average pressure of 8-3 Ibs.
per square inch would only be attained with a maximum of
2i6'6 Ibs. per square inch, thus necessitating great strength of
cylinder and working parts for a very small return in effective
power. In the ' Ericsson,' the average effective pressure was less
than this, being only about 2 Ibs. per square inch ; it had four air
cylinders each of 14 feet diameter, and only indicated 300 horse-
power. Stirling's motor cylinder did not give a true idea of the
bulk of the engine, as the real air-displacer was separate. Even
with Wenham's machine the bulk was excessive, an engine of
24 inches diameter cylinder and 1 2 inches stroke giving 4 horse-
power.
Those facts sufficiently illustrate the practical difficulties which
prevented the development of the hot-air engine proper. All flow
from the method of heating. Low temperature is necessary to
secure durability of the iron.
26 The Gas Engine
All hot-air engines are, therefore, very large and very heavy
for the power they are capable of exerting.
The friction of the parts is so great that although the theoreti-
cal efficiency of the working fluid is higher than in the best steam
engines, the practical efficiency or result per horse available for
external work is not nearly so great. The best result ever claimed
for Stirling's engine is 27 Ibs. of coal per bk. horse-power per
hour, probably under the truth, but even allowing it, a first class
steam engine of to-day will do much better. According to Prof.
Norton, the engines of the * Ericsson ' used 1*87 Ibs. of anthracite
per indicated horse-power per hour ; but the friction must have been
enormous. Compared with the steam engine, the practical disadvan-
tages of the hot-air engine are much greater than its advantage of
theory. Owing to the great inferiority of air to boiling water as a
medium for the convection of hear, the efficiency of the furnace is
much lower ; owing to the high maximum and low available pres-
sure, the friction is much greater— which disadvantages in practice
more than extinguish the higher theoretical efficiency.
The gas engine method of heating by combustion or explosion
at once disposes of those troubles ; it not only widens the limits
of the temperatures at command almost indefinitely, but the causes
of failure with the old method become the very causes of success
with the new method.
The difficulty of heating even the greatest masses of air is
quite abolished. The rapidly moving flash of chemical action
makes it easy to heat any mass, however great, in a minute fraction
of a second ; when once heated the comparatively gradual con-
vection makes the cooling a very slow matter. The conductivity
of air for heat is but slight, and both losing and receiving heat
from enclosing walls are carried on by the process of convection,
the larger the mass of air the smaller the cooling surface relatively.
Therefore the larger the volumes of air used, the more economical
the new method, the more difficult the old. The low conductivity
for heat, the cause of great trouble in hot-air machines, becomes
the unexpected cause of economy in gas engines. If air were a
rapid carrier of heat, cold cylinder gas engines would be impos-
sible. The loss to the sides of the enclosing cylinders would be
so great that but little useful effect could be obtained. Even as
The Gas Engine Method 27
it is, present loss from this cause is sufficiently heavy. In the
earlier engines as much as three-fourths of the whole heat of the
combustion was lost in this way ; in the best modern engines so
much as one-half is still lost.
A little consideration of what is occurring in the gas engine
cylinder at each explosion will show that this is not surprising.
Platinum, the most infusible of metals, melts at about 1700° C;
the ordinary temperature of cast iron flowing from a cupola is
about 1200° C.; a temperature very usual in a gas engine cylinder
is 1600° C., a dazzling white-heat. The whole of the gases filling
the cylinder are at this high temperature. If one could see the
interior it would appear to be filled with a blinding glare of light.
This experiment the writer has tried by means of a small aperture
•covered with a heavy glass plate, carefully protected from the
heat of the explosion by a long cold tube. On looking through
this window while the engine is at work, a continuous glare of
white light is observed. A look into the interior of a boiler
furnace gives a good notion of the flame filling the cylinder of
a gas engine.
At first sight it seems strange that such temperature can be
used with impunity in a working cylinder ; here the convenience
of the method becomes evident. The heating being quite inde-
pendent of the temperature of the walls of the cylinder, by the use
of a water-jacket they can be kept at any desired temperature.
The same property of rapid convection of heat, so useful for
•generating steam from water, is essential in the gas engine to keep
the rubbing surfaces at a reasonable working temperature. In
this there is no difficulty, and notwithstanding the high tempera-
ture of the gases, the metal itself never exceeds the boiling point
of water.
So good a result cannot of course be obtained without careful
proportioning of the cooling surfaces for the amount of heat to be
carried away ; in all modern engines this is carefully attended to,
with the gratifying result that the cylinders take and retain a
polished surface for years of work just as in a good steam engine.
The gas engine method gives the advantage of higher tempera-
ture of working fluid than is attainable in any other heat engine,
at the same time the working cylinder metal may be kept as cool
28 The Gas Engine
as in the steam engine. It also allows of any desired rate of heat-
ing the working fluid in any required volumes.
In consequence of high temperatures the available pressures
are high, and therefore the bulk of the engine is small for the
power obtained.
It realises all the thermodynamic advantages claimed for the
hot-air engine without sacrificing the high available pressures and
rapid rate of the generation of power which is the characteristic of
the steam engine.
For rapid convection of heat existing in the steam boiler is
substituted the still more rapid heating by explosion or combustion,
a rapidity so superior that the power is generated for each stroke
separately as required, there being no necessity to collect a great
magazine of energy.
The only item to the debtor side of the gas engine account
is the flow of heat through the cylinder walls, which disadvantage-
is far more than paid for by the advantages.
29
CHAPTER II.
GAS ENGINES CLASSIFIED.
ALTHOUGH the gas engine patents now in existence number many
hundreds, the essential differences between the inventions are not
great. In their working process they may be divided into a few
well-defined types :
1. Engines igniting at constant volume, but without previous
compression.
2. Engines igniting at constant pressure, with previous com-
pression.
3. Engines igniting at constant volume, with previous com-
pression.
THE FIRST TYPE is the simplest in idea ; it is the most apparent
method of obtaining power from an explosion.
In it the engine draws into its cylinder gas and air at atmos-
pheric pressure, for a part of its stroke, in proportions suitable for
explosion ; then a valve closes the cylinder, and the mixture is
ignited. The pressure produced pushes forward the piston for
the remainder of its travel, and upon the return stroke the pro-
ducts of the combustion are expelled exactly as the exhaust of a
steam engine. By repeating the same process on the other side
of the piston, a kind of double-acting engine is obtained. It is
not truly double-acting, as the motive impulse is not applied
during the whole stroke, but only during that portion of it left
free after performing the necessary function of charging with the
explosive mixture.
The working cycle of the engine consists of four operations :
1. Charging the cylinder with explosive mixture.
2. Exploding the charge.
3. Expanding after explosion.
4. Expelling the burned gases.
3O The Gas Engine
To carry it out in a perfect manner, the mechanism must be-
so arranged that during the charging, the pressure of the gases in
the cylinder does not fall below atmosphere ; there must be no-
throttling of the entering gases. The cut-off and the explosion
must be absolutely simultaneous and also instantaneous, so that
the heat may be applied without change of volume, and thereby
produce the highest pressure which the mixture used is capable
of giving. The expansion will be carried far enough to reduce
the pressure of the explosion to atmosphere ; and the exhaust
stroke will be accomplished without back pressure. The charge
in entering must not be heated by the walls of the cylinder, but
should remain at the temperature of the atmosphere till the very
moment previous to ignition. At the same time, the cylinder
should not cool the gases after the explosion, no heat should dis-
appear except through expansion doing work.
Although all these conditions are necessary to the perfect
cycle, it is evident that no actual engine is capable of combining
them. Some throttling at the admission of the mixture, and a
little back pressure during the exhausting are unavoidable ; some
time must elapse between the closing of the inlet valve and the
explosion, in addition to the time taken by the explosion itself.
Heat will be communicated to the entering gases and lost by the
exploded gases to the walls of the cylinder.
The actual diagram taken from an engine will therefore differ
considerably from the theoretic one.
The theoretical conditions are to a great extent contradictory.
The idea of the type, however, is easily comprehensible, and
evidently suggested by the common knowledge of the destructive
effect of accidental coal gas explosions which occurred soon after
the introduction of gas into general use. * The power is there, let
us use it like steam in the cylinder of a steam engine,' said the
early inventors.
The two most successful engines of this type were Lenoir's
and, later, Hugon's, for very small powers ranging from one man
to half-horse. Simple forms of this type are still in extensive use.
The most widely known of these is the Bisschof, a French inven-
tion.
THE SECOND TYPE is not so simple in its main idea, and required
Gas Engines Classified 3 1
much greater knowledge of detail, both mechanical and theoretical.
As a hot-air engine its theory was originally proposed by Sir Geo.
Cayley, and, later, by Dr. Joule and Sir Wm. Thomson. As a
hot-air engine it failed for the reasons discussed in the previous
chapter.
In it the engine is provided with two cylinders of unequal
capacity ; the smaller serves as a pump for receiving the charge
and compressing it, the larger is the motor cylinder, in which the
charge is expanded during ignition and subsequent to it.
The pump piston, in moving forward, takes in the charge at
atmospheric pressure, in returning compresses it into an inter-
mediate receiver, from which it passes into the motor cylinder in
a compressed state. A contrivance similar to the wire gauze in a
Davy lamp commands the passage between the receiver and the
cylinder, and permits the mixture to be ignited on the cylinder
side -as it flows in without the flame passing back into the
receiver.
The motor cylinder thus receives its working fluid in the state
of flame, at a pressure equal to, but never greater than, the
pressure of compression. At the proper time, the valve between
the motor and the receiver is shut, and the piston expands the
ignited gases till it reaches the end of its stroke, when the exhaust
valve is opened, and the return expels the burned gases.
The ignition here does not increase the pressure, but increases
the volume. The pump, say, puts one volume or cubic foot into
the receiver ; the flame causes it to expand while entering the
cylinder to two cubic feet. It does the work of two cubic feet in
the motor cylinder, so that, though there is no increase of pres-
sure, there is nevertheless an excess of power over that spent in
compressing.
In the first type of engine the heat is given to the working
fluid at constant volume, in the second type the heat is given to
the working fluid at constant pressure during change of volume.
The working cycle of the engine consists of five operations :
1. Charging the pump cylinder with gas and air mixture.
2. Compressing the charge into an intermediate receiver.
3. Admitting the charge to the motor cylinder in the state of
flame, at the pressure of compression.
32 The Gas Engine
4. Expanding after admission.
5. Expelling the burned gases.
To carry out the process perfectly the following conditions
would be required.
No throttling during admission of the charge to the pump.
No heating of the charge as it enters the pump from the
atmosphere.
No loss of the heat of compression to the pump and receiver
walls.
No throttling as the charge enters the motor cylinder from the
receiver.
No loss of heat by the flame to the sides of the motor cylinder
and piston.
And last, No back pressure during the exhaust stroke.
The exhaust gases also must be completely expelled by the
motor piston ; that is, the motor cylinder should have no clear-
ance.
The requirements of this type, although sufficiently numerous
and exacting, are not so contradictory among themselves as in the
first.
Although every engine of the kind yet made fails to fulfil them,
it is quite possible that a machine very closely approximating may
be yet constructed.
The most successful engines of this kind have been Brayton's
and Simon's, the first an American invention, and the second
an English adaptation of it. Sir C. W. Siemens proposed such
an engine in 1861, but does not seem to have been successful in
carrying it out. In 1860 it was also proposed by F. Million, but
without a sufficient understanding of the mechanical detail neces-
sary for a working machine.
Brayton's engine was made in considerable numbers in America,
and was applied by him to drive a good-sized launch, petroleum
being used as the fuel instead of gas. It was exhibited at the Cen-
tennial Exhibition in Philadelphia ; at the Paris exhibition of 1878
by Simon.
THE THIRD TYPE is the best kind of compression engine yet
introduced ; by far the largest number of gas engines in every day
use throughout the world are made in accordance with its require-
Gas Engines Classified 33
ments. In theory it is more easily understood as requiring two
cylinders, compression and power.
The leading idea, compression and ignition at constant volume,
was first proposed by Barnett in 1838, then by Schmidt in more
general terms, very fully by Beau de Rochas in 1860 and also by
F. Million in the same year. Otto, however, was the first to suc-
cessfully apply it, which he did in 1876.
The compression cylinder may be supposed to take in the
charge of gas and air at atmospheric temperature and pressure ;
compress it into a receiver from which the motor cylinder is sup-
plied ; the motor piston to take in its charge from the reservoir in
a compressed state ; and then communication to be cut off and
the compressed charge ignited.
Here ignition is supposed to occur at constant volume, that is,
the whole volume of mixture is first introduced and then fired «•
the pressure therefore increases. The power is obtained by
igniting while the volume remains stationary and the pressure in-
creases.
Under the pressure so produced, the piston completes its
stroke, and upon the return stroke the products of the combus-
tion are expelled.
In this case the working cycle of the engine consists of six
operations :
1. Charging the pump cylinder with gas and air mixture.
2. Compressing the charge into an intermediate receiver.
3. Admitting the charge to the motor cylinder under com-
pression.
4. Igniting the mixture after admission to the motor.
5. Expanding the hot gases after ignition.
6. Expelling the burned gases.
To carry out the process perfectly, similar conditions are neces-
sary to those in the second type. But the conditions are more
contradictory. The gases entering the cylinder under pressure must
not be heated by its walls ; no heat should be added till the igni-
tion ; then, after ignition the gases must not lose heat to the
cylinder— conditions which it is impossible for the same cylinder
to fulfil simultaneously.
In the engines constructed the receiver is dispensed with, for
D
34 The Gas Engine
reasons which will be explained in discussing the practical difficul-
ties of construction ; but this does not in any way modify the
theory, which shall first be discussed.
The most considerably used engine of this kind is the Otto,
next to it coming Clerk's engine, then Robson's by the Messrs.
Tangye, and Andrews' Stockport compression engine. In none
of these types does any part of the working cycle require either
the heating or the cooling of the working fluid by the relatively
slow processes of convection and conduction.
Heating is accomplished by the rapid method of explosion or,
if the term be preferred, combustion, and for the cooling neces-
sary in all heat engines is substituted the complete rejection of
the working fluid with the heat it contains and its replacement by
a fresh portion taken from the atmosphere at the atmospheric
temperature, which is the lower limit of the engines.
This is the reason why those cycles can be repeated with
almost indefinite rapidity, and why gas engines can be run at
speeds equal to steam engines, while the old hot-air engines could
not be run fast, because of the very slow rate at which air could be
heated and cooled by contact.
There still remains one important type of gas engine not
included in this classification ; in it part of the efficiency is de-
pendent on cooling by contact, and consequently only a slow rate
of working stroke can be obtained. It is the kind of engine
known as the free piston or atmospheric gas engine. It may be
regarded as a modification of the first type. The first part of its
action is precisely similar, the latter part differs considerably.
It may be called Type ONE A. In it the piston moves for-
ward, taking in its charge of gas and air from the atmosphere at
the atmospheric pressure and temperature. When cut off it is
ignited instantaneously, the volume being constant and the
pressure increasing ; the piston is not connected directly to the
motor shaft, but is free to move under the pressure of the explo-
sion, like the ball in a cannon. It is shot forward in the cylinder
(which is made purposely very long) ; the energy of the explosion
gives the piston velocity ; it therefore continues to move con-
siderably after the pressure has fallen by expansion to atmos-
phere ; a partial vacuum forms under the piston till its whole
Gas Engines Classified 35
energy of motion is absorbed in doing work upon the exterior
air. It then stops, and the external pressure causes it to perform
its instroke, during which a clutch arrangement yokes it to the
motor shaft, giving the shaft an impulse. The explosion is made
to give its equivalent in work upon the external air, in forming a
vacuum in fact ; the vacuum is increased by the cooling of the
hot gases during the return of the piston. The piston proceeds
completely to the bottom of the cylinder, expelling the products
of combustion. So far as the working fluid of the engine is con-
cerned the cycle consists of five operations :
1. Charging the cylinder with explosive mixture.
2. Exploding the charge.
3. Expanding after explosion.
4. Compressing the burned gases after some cooling.
5. Expelling the burned gases.
To carry it out perfectly, in addition to the requirements of the
first type, the expansion should be carried far enough to lower the
temperature of the working fluid to the temperature of the atmos-
phere, and the compression to atmospheric pressure again should
be conducted at that temperature ; that is, the compression line
should be an isothermal.
This kind of engine was proposed first by Barsanti and Mat-
teucci in 1854, by F. H. Wenham in 1864, and then by Otto and
Langen in 1866. The last named inventors were successful in
overcoming the practical difficulties, and many engines were
made and sold by them. Their engine, although cumbrous and
noisy, was a good and economical worker ; many are still in use.
The next best known engine of the kind was Gillies's, of which a
-considerable number were constructed and sold.
D 2
36 The Gas Engine
CHAPTER III.
THERMODYNAMICS OF THE GAS ENGINE.
BEGINNING with Professor Rankine, able writers have so fully
treated the thermodynamics of the air engine that but little can
be added to the knowledge of the subject now in existence. The
gas engine method of heating, however, introduces limits of
temperature so extended and cycles of action so different from
those possible in the air engine proper, that something remains to
be done in applying the existing data. So far as the author is
aware, this has been previously attempted by three writers only —
Prof. R. Schottler, Dr. A. Witz, and himself.
Before proceeding with the special consideration of the sub-
ject, it is advisable for the sake of completeness to state briefly
the general laws. In doing so Rankine will be followed as closely
as possible.
THERMODYNAMICS DEFINED.
' It is a matter of ordinary observation that heat, by expanding
bodies, is a source of mechanical energy, and conversely, that
mechanical energy, being expended either in compressing bodies
or in friction, is a source of heat.
' The reduction of the laws according to which such phenomena
take place to a physical theory or connected system of principles
constitutes what is called the science o( thermodynamics. '
FIRST LAW OF THERMODYNAMICS.
Heat and mechanical energy are mutually convertible, and
heat requires for its production, and produces by its disappear-
ance, mechanical energy in the proportion of 1,390 footpounds
for each centigrade heat unit, a heat unit being the amount of
Thermodynamics of the Gas Engine 37
heat necessary to heat one pound weight of water through i° C.
This is Joule's law, having been first determined by him in 1843.
It holds with equal truth for other forms of energy, and is a
general statement of the great truth, that in the universe, energy is
as incapable of creation or destruction as matter. Energy may
change its form indefinitely while passing from a higher to a
lower level, but it can neither be created nor destroyed. The
energy of outward and visible movement of matter may be
arrested and caused to disappear as movement of the whole mass
in one direction, but its equivalent reappears as internal move-
ment or agitation of the particles or molecules composing the
body. Energy assumes many forms, but the sum of all remains
a constant quantity, incapable of change of quantity, but capable
of disappearing in one form and reappearing in another.
SECOND LAW OF THERMODYNAMICS.
Although heat and work are mutually convertible and in
definite and invariable proportions, yet no conceivable heat
engine is able to convert all the heat given to it into work.
Apart altogether from practical limitations, a certain portion
of the heat must be passed from the hot body to the cold body in
order that the remainder may assume the form of mechanical
energy. To get a continuous supply of mechanical energy from
heat depends upon getting a continuous supply of hot and cold
substances : it is by the alternate expansion and contraction of
some substance, usually steam or air, that heat is converted into
mechanical energy.
Perfect heat engines are ideal conceptions of machines which
are practically impossible, but whose operations are so arranged
that, if possible, they would convert the greatest conceivable
proportion of the heat given to them into mechanical work.
Efficiency. — The efficiency of a heat engine is the ratio of the
heat converted into mechanical work to the total amount of heat
which enters the engine.
In this work the word Efficiency ', when used without qualifica-
tion, bears this meaning only.
The efficiency of a perfect heat engine depends upon two
38 The Gas Engine
things alone : these are, the temperature of the source of heat and
the temperature of the source of cold (allowing the expression).
The greater the difference between these temperatures the greater
the efficiency. That is, the greater will be the proportion of the
total heat converted into mechanical energy, and the smaller the
proportion of the total heat which necessarily passes by conduction
from the hot to the cold body.
Properties of Gases. — Gases are the most suitable bodies for
use in heat engines ; they are almost perfectly elastic, and they ex-
pand largely under the influence of heat.
A gas is said to be perfect when it completely obeys two
laws :
1. Boyle's law.
2. Charles's law.
Boyle's Law. — Suppose unit volume of gas to be contained in
a cylinder fitted with a piston which is perfectly tight at unit
pressure. Suppose the temperature to be kept perfectly constant.
Then, according to Boyle's law, however the volume may be
changed by moving the piston, the pressure is always inversely
proportional to volume, that is, if volume becomes two, pressure
becomes one-half ; volume becomes three, pressure becomes
one-third.
The product of pressure and volume is always constant.
Denoting pressure by /, and volume by ?<•,
Boyle's law is, p v = constant.
Charles's Law. — If a gas kept at constant volume is heated,
the pressure increases. If a gas is kept behind a piston which
moves without friction so that the pressure upon the gas is always
constant, the heat applied will cause it to expand.
One volume of gas at o° C., if heated through i° C. will expand
^, and become i^|^- volume, if the pressure is constant. If the
volume is constant, then its pressure will increase by ^i^, that is,
its pressure will become IYTU °f the original. In the same way
if cooled i° C. below o° C., it will contract or diminish in pressure
by ^|^, its volume or pressure becoming f ff of what it is at o° C.
For every degree of heat or cold above or below o° C. a perfect
gas expands or contracts by ^\^ of its volume at o° C.
Thermodynamics of the Gas Engine 39
From this it is evident that a perfect gas, if cooled to 273° C.
below o° C. will have neither volume nor pressure.
This originally gave rise to the conception of absolute zero of
temperature. The absolute temperature of a body is ordinary
temperature Centigrade + 273, just as the absolute pressure of any
gas is its pressure above atmosphere plus atmospheric pressure. The
absolute temperature of a body is its temperature above Centigrade
zero + 273.
The pressure or volume of a gas is therefore directly propor-
tional to its absolute temperature.
If p=. pressure for absolute temperature /, and pl pressure for
tl temperature, also absolute,
or if v be the volume at absolute temperature / and vl at /l,
*- ?-£
The Second Law (quantitative}. — If heat be supplied to a perfect
heat engine at the absolute temperature T1, and the absolute tem-
perature of the source of cold is T, then the efficiency of that
engine is, denoting it by E,
E_T'~T_ I
H. — - ; - — I ~ — ..
Tl Tl
It is unity minus the lower temperature divided by the upper
temperature. The efficiency is greater or less as the fraction ^
is less or greater. This fraction may be diminished either by
reducing T or by increasing T1. The lowest available temperature
is not capable of great variation, being in our climate about 290°
absolute. It therefore follows that efficiency could only be in-
creased by increasing T1.
Suppose T=29o° absolute and T1=58o° absolute.
Then E = i - ff£ = i - i = 0-5.
Suppose T=29o°, and T1 = i45o°, a temperature common in
gas engines, then
40
The Gas Engine
The efficiency increases with increase of the maximum tempe-
rature. The second law, in its quantitative form, is the statement
of the efficiency of any perfect heat engine in terms of absolute
temperatures of the source of heat and the source of cold.
Thermal Lines. — If a volume of air is contained in a cylinder
having a piston and fitted with an indicator, the piston, if moved
to and fro, will alternately compress and expand the air, and the
indicator pencil will trace a line or lines upon the card, which lines
register the change of pressure and volume occurring in the cylinder.
If the piston is perfectly free from leakage, and it be supposed that
the temperature of the air is kept quite constant, then the line so
traced is called an Isothermal line, and the pressure at any point
when multiplied by the volume is a constant according to Boyle's
law,
pv = a constant.
If, however, the piston is moved in very rapidly, the air will not
remain at constant temperature, but the temperature will increase
because work has been done upon the air, and the heat has no
E
33
0 <
j
\
\
\-
31
7'
f
s
V
x°ri
J
?<•
^
s
'
,)6
^
<•
^
•
C
H
^
^
'I
Atmospheric line
6 10 20 30 40 50 60 70 80 90 100
VOLUME.
Compression lines for air (dry), Adiabatic and Isothermal.
FIG. 10.
time to escape by conduction. If no. heat whatever is lost by any
cause, the line will be traced over and over again by the indicator
pencil, the cooling by expansion doing work precisely equalling
the heating by compression. This is the line of no transmission
of heat, therefore, known as Adiabatic. Fig. 10 shows these two
Thermodynamics of the Gas Engine 41
lines for air starting from atmospheric pressure and tempera-
ture.
The pressures at different points of the curve are related by the
equation
pvy = constant.
The pressure when multiplied by the volume raised to the y power
is always constant.
The power jy is the ratio between the specific heat of the air at
constant pressure and its specific heat at constant volume. Ac-
cording to Rankine
y = i 408 for air.
Imperfect Heat Engines. — For a complete description of the
working cycle of perfect heat engines, the reader is referred to
works upon the steam engine, which contain the fullest possible
details both of reasoning and results.
The working cycles of practicable heat engines are always im-
perfect, that is, the operations are such that, although perfectly
carried out, the maximum efficiency possible by the second law of
thermodynamics could not be attained by them. Each cycle has
a maximum efficiency peculiar to itself, which is invariably less
Ti T
than j— , but which does not necessarily vary with T1 and T.
It does not always follow that increase of the higher tempera-
ture causes increase of efficiency ; conversely, it does not always
follow that diminution of the upper temperature causes diminution
of efficiency. Under some circumstances, indeed, the opposite
effect is produced — increase of the upper temperature diminishes
efficiency, while its diminution increases it, of course within certain
limits.
All the gas engine cycles described in the previous chapter are
imperfect in this sense, but all are practicable. It follows that if
any one of them gives a higher efficiency than another in theory,
it will also do so in practice, provided the practical losses do not in-
crease with improved theory.
It is necessary before discussing the practical losses to see how
the cycles compare with each other, if each be perfectly carried
out. The results obtained can then be modified by examination
of the way in which unavoidable practical losses affect each cycle.
42 The Gas Engine
EFFICIENCY FORMUL/E.
If H is the quantity of heat given to an engine, and H1 the
amount of heat discharged by it after performing work, then, the
portion which has disappeared in performing work is H — H1,
supposing no loss of heat by conduction or other cause,. and the
efficiency of the engine is
__ H — H1
H
Type i. — A perfect indicator diagram of an engine of this kind
is shown at fig. 1 1 : the line a b c is the atmospheric line, represent-
ing volume swept by the piston, the line a d is the line of pressures.
From a to b the piston moves forward, taking in its charge, at
atmospheric temperature and pressure; at b communication is in-
stantaneously cut off, and heat instantaneously supplied, raising
the temperature to the maximum, before the movement of the pis-
ton has time to change the volume. From £, the point of maxi-
mum temperature and pressure, the gases expand without loss of
heat, the temperature only falling by reason of work performed
till the pressure again reaches atmosphere. The curve e c is
therefore adiabatic. In all cases let
/ be the initial temperature of the air in absolute degrees Centi-
grade.
T the absolute temperature after explosion or heating.
T l the absolute temperature of the gases after adiabatic ex-
pansion.
p the atmospheric pressure.
PO the absolute pressure of the explosion.
V0 the volume at atmospheric temperature and pressure.
v the volume at the termination of adiabatic expansion.
In the particular case of diagram fig. n, where the expansion
is continued to the atmospheric line, the formula expressing the
efficiency is very simple. Calling KV the specific heat of air at
constant volume, and K, the sp. heat at constant pressure, then
the heat supplied to the engine is
Thermodynamics of the Gas Engine
43
* o
U
v^»'
P
d
S
I I I I I
I I I J| IH I
»v> V> %»»fc V>
d
e
a - -•y
•J-: " ."«
£ V
* S ~
o 3
*£3
44 The Gas Engine
and the heat discharged from it is
therefore efficiency is
E = — — £-i
and %
K,
therefore I
It is evident that for every value of T there is a corresponding
value of T1, which increases with the increase of T. If T1 is
known in terms of T, then the calculation of efficiency is very
rapid, as all that is required is a knowledge of the maximum
temperature of the explosion to calculate the efficiency of an
engine using that maximum temperature, and perfectly fulfilling
this cycle.
For any adiabatic curve, the pressure multiplied by volume
which has been raised to the jyth power is a constant; there-
fore
?0 v0y =p0vy (see diagram, fig. 1 1 ), (a)
and 1=^2 which, as / =/„ is the same as ^ ;
i V T*
also -=— .
v0 t
«*. in equation (a) T may be substituted for p,, / for/,, t for v0, and
T! for z', giving
T1 =
In most engines of this type the expansion is not great enough
to reduce the pressure to atmosphere before opening the exhaust
valve ; it is therefore necessary to give formulae where the best
condition is not carried out. Fig. 12 is a diagram of a case of
this kind.
The pressure at the termination of the stroke has fallen to /„,
Thermodynamics of the Gas Engine 45
and the temperature to T1. The heat supplied to the engine is
the same as in the first case
H = KW(T-/).
The heat discharged by it cannot be so simply expressed.
Suppose the hot gases at the pressure p0 to be allowed to cool by
contact with the sides of the cylinder at constant volume till the
atmospheric pressure/ is reached, then the temperature
or in terms of volume and / tl = - /,
and the heat lost is KV (x1 — /l \
The heat to be still abstracted before the air returns to its
original condition at /, and pressure/ is
K, (/'-/).
Total heat discharged by exhaust, therefore,
HI = KZ;(TI ->).+ K*( /»-/).
The efficiency consequently is
K, (T -/)- (K, (T'- /i) + K, (;*-/)}
In this case there is no fixed relationship between T the tempera-
ture of the explosion, and T1 the temperature of the gases at the
termination of adiabatic expansion. As the expansion is more or
less complete, so does T and T1 change. In no case, however,
can the efficiency be so great as that in the first case.
Type 2. — A perfect indicated diagram of an engine of this type
is shown at fig. 13. Although the cycle requires two cylinders,
producing two diagrams, they are better compared when super-
posed. The whole diagram may be supposed to come from the
motor cylinder, the shaded portion of it representing the available
work of the cycle, and the unshaded part, the part done by the
compressing pump. The atmospheric line is a be. The pump
volume is a b, the motor volume is a c. The pump takes in the
volume ab at atmospheric pressure ; it compresses it into an
46 The Gas Engine
intermediate receiver, the compression line (adiabatic) is bf,
passing into receiver, line fe. From the receiver it enters the
cylinder at the constant pressure of compression on the line efg,
supply of heat cut off at g. Then expansion (adiabatic) to the
point c atmospheric pressure. The part bfgc is the part avaiL
able for work, the part bfe a representing the work of the com*
pressing pump, which is deducted from the total motor cylinder,
diagram aegc.
The total volume of air passed through the pump is #„ volume
swept by motor cylinder, v. So far as the heat operations are
concerned, the part of the diagram to volume vc may be disre-
garded ; it represents the pressing of the compressed charge into
the reservoir after reaching the maximum pressure of compression
(it is called vc because it is volume of compression). The admis-
sion to the motor cylinder is identical, so that work done in pump
in that part equals work done upon the motor piston.
In addition to the letters used in type i,
vc is volume of compression.
vp volume at point g on diagram.
pc is pressure of compression.
tc is temperature of compression.
The temperature, volume, and pressure letters are figured
below the diagram to make matters clear. Compression is carried
on from volume v0 at atmospheric pressure and temperature to
volume vc at pressure pc and temperature fa the curve being
adiabatic.
After compression, heat is added without allowing the pres-
sure to increase, but the piston moves out till the maximum tem-
perature T is attained, and the supply of heat being completely cut
off, adiabatic expansion follows till the atmospheric pressure is
reached ; the exhaust valve is then opened, and the hot gases dis-
charged.
It is evident that as the pressure is constant, while heat is
being given, the amount of heat given to the engine in all is
H = K, (T - /,),
and the heat discharged from it is also at constant pressure,
H1 = K, (T1 - /).
Thermodynamics of tJie Gas Engine
47
I = :|
o s
w s
g*"S^
fit
K> <o X"^ ^ S 00 *>
« «
<u i»
a -
o,
- - o
o
a
g{Ux*»*t
B
•e 2
•2§^
1^^
c
£
N
i
48 The Gas Engine
The efficiency is therefore
._ i^p \ • WCI "V \" f
K,(T-/,)
-i-T-i=-5 (4)
The compression and expansion curves being adiabatic,
Compression pc v? = p #/,
Expansion pc v/ = p0vy\
sothat= ' (a)
v} v>
and -' = /c, also ^' = * .
Vp T V T1
Substituting in equation (a)
tc _ *
T T1'
and??--'.
As the efficiency is
T1 /
it may be either = i — — or = i -- (5)
T fc
That is, when expansion is carried to the same pressure as existed
before compression, the efficiency depends upon the compression
alone, / being the temperature before compression, and tc the tem-
perature of compression. The efficiency being i — -, the greater
*c
the temperature tc the less is the fraction -, and the more nearly
*c
does E approach unity.
In most working engines of this kind, the expansion is not
continued long enough to make the pressure after expanding fall
to atmosphere ; so that the efficiency is never so great, as when that
is done, a greater portion of the heat is discharged than need be.
Thermodynamics of the Gas Engine 49
The modification of the formulae is precisely as in type i for
similar circumstances. A diagram of the kind is shown at fig. 14.
The temperature fi is found as before :
/i = T'A.
Po
The heat supplied to the cycle is as before :
H = K, (T - 4),
and the heat discharged is
H1 = K, (T1 - /l) + K, (f1 - /).
The efficiency is
- (T1 - />) + (f1 ~ /)
E=I-^___r/: (6)
Although there is no fixed proportion between the efficiency and
the temperature of adiabatic compression, it is evident that E in-
creases with increase of tc
Type 3. — A perfect indicator diagram of an engine of this type
is shown at fig. 15. As in type 2, the diagrams of pump and
motor are combined, the whole diagram being that given in the
motor cylinder, but the shaded portion only represents the avail-
able work. The atmospheric line is a b c. The pump volume is
a b, the motor cylinder volume is a c. The pump takes in the
volume a b at atmospheric pressure, compresses it on the adiabatic
line bf and into a receiver on the line/^. The compressed gases
enter the motor cylinder on the line gf, heat is added instantane-
ously, and the pressure rises on the line fe. Supply of heat cut
off at e and the expansion line e c is adiabatic. The total diagram
in the motor cylinder is a g f e c, but the portion a g f b is
common to motor and pump ; the available work is therefore
bfec.
The total volume of air passed through the pump is v0 ; the
volume after adiabatic compression, from atmospheric pressure p
and temperature / to pressure of compression pc and temperature
4 is vc Heat is supplied at constant volume vc till the maximum
temperature of the explosion T is attained. The piston then
expands the hot gases adiabatically from temperature T to T1
and pressure ?„ to pressure /„, which in this case is equal to
atmosphere.
E
5<3 The Gas Engine
The heat is discharged in passing from volume v to v0 at con-
stant pressure of atmosphere. The part of the diagram from
volume vc to zero may be disregarded as it is common to both
pump and motor.
The heat supplied to the cycle is
Thermodynamics of the Gas Engine 5 1
Heat discharged
H1 = Kp (T1-/).
The efficiency is
T1-/
It is evident that for any maximum temperature T and com-
pression temperature tc there is a temperature TI at which the
expansion adiabatic line falls to atmosphere. It will much sim-
plify subsequent calculations to establish the relations between T,
tt, t and x1.
pov* = p0vv and pp? = pv? and as A=A
PC Vo*
but - =- so that -^ = I1:
v0 t A fv
T /T* N-^
and ~ = — so that
A tc
T1 in terms of T, tc and / is therefore
T1 = / (L\ 7. (8)
Although this is the best case for the third type it is not the
one commonly occurring in practice ; no engine has as yet been
arranged to expand the gases after explosion to the atmospheric
pressure.
Fig. 1 6 is a perfect diagram of the most common case, namely,
when the expansion is carried only so far that the heat is dis-
charged when the volume is the same as that existing before com-
pression. The formula of efficiency is exceedingly simple, and
leads to a very apparent and nevertheless somewhat paradoxical
result.
The heat supplied to the cycle is
H = Kv (T - /,),
and the heat discharged is
H' = K. (T' - t),
E 2
52 The Gas Engine
because the volume of the air is the same as that existing before
compression, and therefore the heat necessary to bring the fluid
back to its original state can be abstracted at constant volume.
•i '2 '3 '4 '5 '6 '7 '8 '9
I'O
VOLUMES.
t absolute temp. CC. at b p absolute pressure at b
T ,, ,, £ vo volume at b
T1 » c v » c
vc „ f
Here v0 = v.
FIG. 16.
Type 3. Perfect diagram. Expansion to same vol. as before compression.
The efficiency is
_ K, (T - /,) - K, (T1 - /)
MT-/,)
As both curves are adiabatic, and pass through the same volume
change,
Thermodynamics of the Gas Engine 53
so that tz£- -t-1.
T - te T te
The efficiency may therefore be expressed
T1 /
E = i — - or i — - (TO)
T tc
or
v
That is, the efficiency depends upon the ratio between the
initial temperature and the temperature of adiabatic compression
only. T, the temperature of explosion, may be any value greater
than ta without either increasing or diminishing the efficiency.
In this case
There is still another case of this type of cycle to be con-
sidered, when the expansion is continued beyond the original
volume before compression, but not carried far enough to reach
atmospheric pressure. Fig. 1 7 is a diagram of the kind.
The heat supplied to the cycle is still
H = K, (T - /,).
The heat discharged may be found as in a similar case with
types i and 2.
Total heat discharged is
HI=KW(T»- /') + Kj(tl - /).
The efficiency is
K* (T " O ~ {K» (T1 - /') + K, (/i - /)}
K, (T - /,)
Here then is no constant relationship between T1 and T ;
the value of the cycle lies between cases ist and 2nd.. The
efficiency is less than in the first case, but greater than in the
second.
Type i A. — In this type of engine the efficiency cannot be
stated in terms of temperature directly because of the nature of the
perfect cycle.
54
The Gas Engine
100
po
Bo
70
60
5"
41 1
3"
i
I I 1 I I I I I I I I I I I i I I I I
•i '2 -3 '4 '5 '6 -7 '8 '9 | 'I '2 '3 4 '5 '6 '7 -8 'g
I'D
VOLUMES.
t absolute temp. CC. at b p absolute pressure at b
„ „
volume at
f
FiG. 17. — Type 3. Perfect diagram. Incomplete expansion.
< 4
H
K 3
o 12345 6y8gi
VOLUMES
FiG. 1 8 — Type IA. Perfect diagram. Limited expansion.
Thermodynamics of the Gas Engine 5 5
The expansion line is adiabatic, and the compression line
whereby all the heat is discharged is isothermal.1
Fig. 1 8 is the theoretical diagram of such an engine. The
scale is altered from previous diagrams because of the great ex-
pansion.
There is no compression previous to the addition of heat, the
heat is added at constant volume vm which is the volume of the
charge. The pressure rises with the temperature from atmos-
pheric pressure p and temperature / to maximum pressure P, and
temperature T. From T the expansion line is adiabatic, and is
continued far enough to reduce the temperature again to t. The
piston then returns, compressing the gases at the temperature / till
the original volume v0 and pressure p are attained.
For any two temperatures t and T there is evidently a
constant relationship between the available work and work dis-
charged as heat. As in expanding from highest to lowest tem-
perature the temperature falls from T to /, the whole area of
the diagram TVOV t, may be. taken as the heat supplied to the
cycle.
The heat rejected is discharged at constant temperature /, and
is equivalent to the area v0 v 1 1.
For any adiabatic curve the area Tv0 v t is
area = -_1_ (p. v0 - p0 v). (12)
For any isothermal
&rea.vffvff
The efficiency is therefore —
&rea.vffvff — pv0 Log. e — . (13)
OK-'
= i ^ T-. -^ (M)
1 In Dr. A. Witz's able work, Etudes sur les moteurs a gaz tonnant, he falls
into the error of supposing both expanding and compression lines of this type adi-
abatic, and he accordingly greatly over-estimates the efficiency proper to it.
56 The Gas Engine
but, as the line of compression discharging heat is an isothermal,
that is, the temperature is kept constant at / during compression
from the lowest pressure to atmosphere,
pv0 = p'0v (Boyle's law).
The efficiency may therefore be written
E = I
(y— i)/Log.
i --
then _.
t~ p
The efficiency can therefore be given entirely in terms of T and /
E=I- - - _ _ =i- __ 1. (15)
T— / T— t
In the case where the expansion is not carried far enough to
bring the temperature of explosion down to the temperature of the
atmosphere, the efficiency can be found by using the formulae
12 and 13 to get proportions of available and total work, and then
get from the nature of the compression curve the total heat dis-
charged. As this is variable it will be better to study it from a
numerical example later on.
The diagram given is the best possible for this kind of cycle.
EFFICIENCY FORMULAE FOR THE DIFFERENT TYPES.
The general formulae for efficiency of the four kinds of cycle
are as follows.
TYPE i, ist Case :
= i - y
T1 in terms of T and /:
Thermodynamics of the Gas Engine 57
2nd Case :
(T^/Dj^Jf - /)
t-t (17)
TYPE 2, TJ
E-I T'~' •
F^T' (is)
also E =r I — — ,
2«</ Caw :
I
. E = I-^ 7^7t (19)
TYPE 3, ist Case :
..,-.>*J^
T - X, (2°)
T1 in terms of T and / :
Case:
E=~ " ' (21)
also E = i — — .
yd Case :
(Tl - /I) + y (/I _ /)
E ^— I ** " — . / v
T - /, (22)
TYPE i A :
/ (y - i) Log. e ( 1 ) ^ t Log. £ I
Those formulae will be found very convenient in rapidly calcu-
lating the theoretical efficiency for any kind of diagram, but they
do not throw much light upon the relative advantage of the differ-
ent types. In type i, for instance, it is apparent that efficiency
Ti f
increases with increase of temperature because the fraction
58 The Gas Engine
becomes less with increase of T, but it does not rapidly become
less because TI also increases with increase of T.
In type 2, ist case, the efficiency is quite independent of T,
and is dependent only on the ratio between t and /c or v0 and vc.
Increase of T (maximum temperature) increases the available
portion of the engine diagram, and therefore the average pressure,
but without altering the efficiency.
TYPE 3. — With this type it is easy to see (ist case) that the
efficiency is greater than in type i, but only a numerical example
will show the proportion.
In the second case it may be greater or less than in type i,
depending altogether on the amount of the compression.
To obtain a clear idea of the relative values of the efficiencies,
it is necessary to calculate a few numerical examples.
CALCULATED EXAMPLES OF EFFICIENCY OF THE TYPES.
Numerical Examples. — Using air as the working fluid, the
value of y, the ratio of specific heat at constant volume to specific
heat at constant pressure is i '408.
Jv =y = 1-408.
K«,
The gaseous mixture used in a gas engine differs considerably
from pure air in its composition, and consequently in the ratio
between specific heat at constant volume, and specific heat at con-
stant pressure, but it is advisable in the first place to consider the
cycle as using air pure and simple. So many circumstances
modify the theoretic efficiency in actual practice that they can be
best considered after studying the simpler cases.
The temperature 1600° C. is a very usual one in the cylinder
of a gas engine, and it will be calculated in each instance as the
maximum, 17° C. being taken as atmospheric temperature.
A similar set with 1000° C. as the maximum will be calcu-
lated to show in each case the change of efficiency, if any, with
change of maximum temperature.
TYPE i. — ist Case. The expansion is continued to atmos-
pheric pressure.
Taking T — 1600° C. = 1873° absolute.
/= 17° C. = 290° „
Thermodynamics of the Gas Engine 59
Then T1 = the temperature after adiabatic expansion to
atmospheric pressure.
T1 = 290 (~— ) I>4°8 = 1090° absolute.
The efficiency is
E = i - JT^-/ = i - r4o8 - = 0-29
T - / 1873 - 290
E = 0*29 with maximum temperature of 1600° C.
Taking the maximum temperature of explosion as 1000° C.
Absolute
T = 1273° = 1000° C.
/= 290°= 17° C
then T1 = 829°.
=
1273 - 290
E = 0-23 with maximum temperature of explosion as 1000° C.
In this cycle the efficiency evidently increases with increase of
the temperature of the explosion, but not in proportion to the
increase of temperature ; a change of maximum temperature from
1000° to 1600° C. only causing the efficiency to rise from 0^23
to 0*29. That is, at the first temperature, 23 heat units out of
every 100 given to the cycle will be converted into work,
while with the second much higher temperature, only 29 units of
100 will be converted into work.
The second case of this type is the one most commonly occur-
ring in practice. The cylinder is so arranged that the charge is
taken in for half- stroke, the explosion then occurs, and the piston
completes its stroke, expanding the heated gases from one volume
to two volumes.
In the diagram, fig. 12, suppose volume v to be equal to
2 v0, and
T = 1873° absolute.
* = 290°
To get T1,
'.
V
60 The Gas Engine
T1 = 1873 (— )°4 = Hn0 absolute.
To calculate efficiency tl is still required ; it is, in terms of
volume and /,
/! = -t = - 2 90 = 580° absolute.
v, i
The efficiency can now be obtained from formula (17).
T — /
+ 1-408(580 — 290)
1873 - 29°
9o = 0.22 nearl
1583
For this case E = 0*22,
showing the effect of limiting the expansion and discharging at a
pressure above atmosphere.
Taking the same ratio of expansion and the lower maximum-
temperature of 1000° C.
T = 1273° absolute.
f =. 290°
as before, T1 = T(- V = 1273 f— J = 959° absolute,
and /! is still 290 x 2 = 580° absolute.
Therefore E = 0*20.
Here the diminution of efficiency due to diminished expan-
sion is not so great as in the first, or rather the higher, tempera-
ture,
with complete expansion 1000° C. giving 0-23,
„ limited „ 1000° C. „ 0-20 ;
with the higher temperature of 1600° C.,
with complete expansion 1600° C. giving 0-29,
., limited „ 1600° C. „ o-22.
It is evident from these results that where the amount of ex-
Thermodynamics of the Gas Engine 61
pansion is from one volume to two volumes, as in the Lenoir and
Hugon engines, the efficiency does not substantially improve with
increasing temperature.
TYPE 2. — \st Case. Where the expansion is carried far enough
to reduce the working pressure to atmosphere, the efficiency of
this kind of engine is quite independent of the temperature of
combustion. This is shown by Professor Rankine 1 in his work on
the steam engine. Whether the heat added after compression
be great or small in amount, the proportion of it which is con-
verted into work is stationary.
The compression most commonly used in this kind of engine
is 60 Ibs. per sq. in. above atmosphere, 75 Ibs. per sq. in. absolute,
taking the atmospheric pressure as 15 Ibs. per sq. in.
The compression is, as before stated, adiabatic ; no heat is
lost or gained. The temperature rises simply because of work
performed upon the air.
Let
Atmospheric temperature and pressure (absolute) /,/ = 290° — 15
Compression, „ „ „ tapc= -75
tc = 290 - 9 = 462-5° absolute,
E=I -_
462-5
E = 0-37.
This result is much better than any obtained with the first
type. It holds equally good for all combustion temperatures :
wkh either 1000° C. or 1600° C. the efficiency would still be
0-37, so long as that degree of compression was used. With a
higher compression the efficiency increases ; 100 Ibs. per sq. in.
above atmosphere is quite a workable degree of compression. It
is instructive to calculate the efficiency with this pressure :
1 The Steam Engine, Prof. Rankine, p. 373, Formula (7).
62 The Gas Engine
t = 290° absolute.
p = 15 Ibs. per sq. in. absolute.
PC **5 ">•> •>"> » 55
(I I t\ \ °'29
•_D-J =524° nearly.
,£=!-?£?« 0-45.
524
E = 0-45.
This type is evidently much superior to the first type, as it i?
capable of greatly increased efficiency by the mere increase of
compression.
In the engines in practice expansion has not been carried far
enough to give the results calculated above. It has been usual to
construct the engine so that the compression pump is one-half of
the volume of the motor cylinder, that is, the ratio of the expan
sion is from one volume to two volumes at atmosphere. Taking
first a compression of 60 Ibs. per sq. in. above atmosphere with this
proportion between the volumes at atmosphere, and the highest
temperature as 1600° C, then (diagram, fig. 13)
T = 1873° absolute.
/ = 290° „
4 = 462-5° .
t1 = 290 X 2 = 580.
Before getting T1 it is necessary to get the volume vt at the
highest temperature. It is
and
c — v0 \j-\y = i f^V«* = 0-318
and x1 = T C^Y".1 = i873/"i^y40 = 1566° absolute.
The efficiency can now be found by formula (19)
i(Ti- /i) + (/'-/) ^(1566 -580) + (580 -290)
E = I — <- - = I —<- _
T — tc 1873 — 462-5
Thermodynamics of the Gas Engine 63
= i _ 071 (986) + 290 = z _ = Q
1410-5
E = 0-30.
Here the insufficient expansion has caused the efficiency possible
from the compression to fall from 0*37 to 0-30.
Calculating in the same way for the greater compression of
100 Ibs. per sq. in. above atmosphere, with expansion ratio between
compression and motor cylinders of two, it is found that the result
is improved.
Here vc = 0-235 v0^
and Vp = 0*841 vol.
T, = T = I8?3 = IJI8
T = 1873°
/ = 290°
P = 580°
tc = 5240
The efficiency is therefore
tr = T_
T—ff 1873 — 524
_ t _ 071 X 738 + 290 =I_^14 = 0.40
1349 T349
E = 0*40.
The greater compression has greatly increased the efficiency
while leaving the proportion of the two cylinders unaltered.
Still using the same cylinders, the efficiency with compression
of 60 Ibs. above atmosphere and a maximum temperature of
1000° C, is
E = 0*36 nearly,
the data being
x1 = 906° T = 1273°
/i = 580° / = 290°
*c = 4620,
volumes
VP= I V = 2
?;£:= 0*318 #„= 0*87.
64 The Gas Engine
Using the higher compression 100 Ibs. above atmosphere with
1000° C. as highest temperature
Data: TI= 763° T =1273°
/i = 580° / = 290°
4= 524°
Vol. : v0 = i 7' = 2
?;c = 0-235 z> = 0-57
In this kind of engine the best result is always obtained when
the expansion is carried to atmospheric pressure. The necessary
proportion between the two cylinders, to accomplish this, depends
on two things : the temperature of compression, and the tempera-
ture of combustion. The ratio between the cylinders should be
With a temperature of compression of 462°, for instance,
and a maximum of 1873° absolute ( —2$ = 4^05 J the volume of
the motor cylinder would require to be 4-05 times that of the
pump. With the increased compression giving 524° absolute
( — 12-= 3*57) ratio of motor to pump 3-57 to i.
\524 /
With the lower maximum temperature of 1273° the ratios for
the two compression values are
= 275 I2-7-3- = 2-43 nearly.
462 524
These figures explain why the efficiency varies so much with
two cylinders of ratio i to 2 with change of maximum temperature
and compression.
TYPE 3. — ist Case. In this case expansion is carried to atmo-
sphere. It is evident from the formulae that efficiency varies to
some extent with maximum temperature of the explosion.
Taking first a maximum temperature of 1600° C, as in the last
type calculated, with a pressure of compression 60 Ibs. above
atmosphere,
The data are as follows :
Temperatures T=i873° / = 290
/, = 462.
Thermodynamics of the Gas Engine
in terms of T and /, /,, is (see p. 57)
T1 = 783°.
The efficiency therefore
E = i -y = i - 1-408
1873 -
E = 0*51.
With compression 100 Ibs. above atmosphere,
^ — 524°
and T1 is therefore x1 = 290
and E = i — 1-408
V524/
545 - 290
1873 - 524
E = 0-55.
Taking, next, 1000° C. as the highest temperature, first with
the lower compression, and after with the higher compression,
with 60 Ibs. compression T1 is 595° absolute
with 100 „ x1 is 545°
E = o'47 at 60 Ibs., E = 0-52 at 100 Ibs., with 1000° C.
In this case the efficiency varies both with the maximum tem-
perature of the explosion and the compression temperature previous
to explosion. A glance at the numbers placed together will show
clearly the relationship.
Max. temps, in °C. . . . 1600° 1600° 1000° 1000°
Pressure of compression above atmo-
sphere 60 Ibs. loolbs. 60 Ibs. 100 Ibs.
Efficiency 0*51 073 0-47 0-52
2nd Case. — Here the expansion after explosion is not carried
on far enough to reduce the pressure to atmosphere. It terminates
when the volume is the same as existed before compression, that is,
the volume swept by the motor piston in expanding doing work is
identical with that swept by the pump piston in compressing up to
maximum pressure. Pump and motor are equal in volume. To this
case of type 3 belong all compression engines in which the motor
piston compresses its charge into a space at the end of the cylinder.
F
66 The Gas Engine
In this case, as in case i, type 2, the theoretic efficiency of the
engine is quite independent of the maximum temperature of the
explosion. So long as the volume after expansion is the same as
that before compression, it does not matter in the least how much
heat is added at constant volume of compression ; whether only a
few degrees rise occurs or 1000° or 2000°, it is all the same so
far as the proportion of added heat converted into work is con-
cerned. That proportion depends solely upon the amount of
compression.
For 60 Ibs. adiabatic compression, temperature 462° absolute,
the efficiency is 0*37 ; for 100 Ibs. above atmosphere it is 0*45. Given
by the formula E =• i — — . (See p. 57.)
*c
E depends absolutely upon the temperature of the atmosphere
and the temperature of compression / and tc. If the relative
volumes of space swept by piston and compression space be known,
then the efficiency can be at once calculated.
yd Case. — Here the expansion is carried further than the
original volume before compression, but not far enough to reduce
the pressure to atmosphere. Efficiency is always less than in the
first case with corresponding temperature of explosion and compres-
sion, but greater than in the second case. It is found by the
formula :
E ±= i - (T1 - /») + y (fl - /)
T - tc
tl depends on the relationship between the volumes v0 and v the
volume at atmosphere and the volume of discharge after expansion.
it is always :
T1 is also found by the same method as in types i and 2. It is
better to postpone calculating any particular case of this at present,
as no engine doing this has yet got into public use, and it can be
considered further on in discussing the effect, of increased expan-
sion in the actual engines.
Type i A.— The efficiency of this type of heat cycle depends
to a considerable extent upon cooling during the return stroke ;
in its best form, cooling at the lowest temperature during isother-
Thermodynamics of the Gas Engine 67
mal compression, it cannot be carried out without introducing the
very disadvantages with which the hot-air engine was saddled,
namely, a dependence upon the slow convection of air for the
discharge of the heat necessarily rejected from the cycle. The
rapid performance of this operation is impossible, and accordingly
it is hardly fair to compare this type with those preceding ; they
could all of them be greatly improved in theory by introducing
greater expansions and cooling by convection at the lowest tempe-
rature, but all at the expense of rate of working. The efficiency
of type i A, will be found to be high ; but it is to be kept con-
stantly in mind that the penalty of slow rate of work was fully
exacted in the practical examples of the kind in public use. They
are exceedingly cumbrous, and give but a trifling power in com-
parison with their bulk and weight. The efficiency in this type is
dependent upon T and t only.
/'T
(y - i) /Log. t -
T — t T-/
Take first T=i873°
/= 290°
290 x 1*865
1583
E = o'66.
This is a very high efficiency, but it is obtained by using an
enormous expansion,
1) I T \ *
— = ( — Y-* = 967 nearly.
The piston must move through nearly 100 times the original
volume of the charge before the temperature is reduced to the
temperature existing before igniting ; in passing back to unit
volume the gases must be supposed to keep at / by the cooling
effect of the cylinder walls.
When T = 1000° C. = 1273° absolute,
/= i7°C. = 290° „
the efficiency is
. £ = 0-56,
and the expansion required is not so great, being 37-5 volumes.
F 2
68
The Gas Engine
The actual ratios of expansion used in practice have not ap-
proached those proportions, and will be considered while discuss-
ing the diagrams taken from engines of this type.
COMPARISON OF RESULTS.
The two maximum temperatures used, 1600° C. and 1000° C.,.
with the lowest temperature, 17° C., give in a perfect heat-engine,,
efficiencies
1600° C. = 0-85 nearly,
1000° C. = 077 „
One case in type 3 comes nearer to a perfect heat-engine than
any of the others. To compare easily the following table will be
useful.
TABLE OF THEORETIC EFFICIENCY.
Max. temp. °C.
Compression
Efficiency
Temp. Pressure
Type i.
.
abs.^C.
above atmos.
Expanding to atmosphere
1600°
0'29
ii ii > i
1000°
—
—
0*23
Expanding to twice volume
) 1600°
—
O'22
existing before ignition
1 1000°
—
—
0'20
Type*.
Expanding to atmosphere
—
462°
60 Ibs.
0'37
ii ii ii
—
524°
100 Ibs.
/ 1600°
462°
60 Ibs.
o'3o
Expanding to twice volume
existing before compression
1600°
1000°
5*4°
462°
100 Ibs.
60 Ibs.
0-40
0-36
^ 1000°
524°
LOO Ibs.
0-44
Type 3.
Expanding to atmosphere
1600°
462°
60 Ibs.
0-51
ii ii n
1600°
524°
loo Ibs.
o'55
• i 11 M
1000°
462°
60 Ibs.
0-47
ii ii ii
IOOOJ
5240
100 Ibs.
0-52
Expanding to the same
1
volume as existed before
f
462°
60 Ibs.
°'37
compressing
) t
^24°
100 Ibs.
°'45
Expanding to greater volume
\
than existed before com-
pressing, but not enough
to reach atmosphere
! Efficiency between ist and 2nd cases of this type
1 depending on ratio of expansion.
Type i A.
Expanding from max. temp.
1600° —
0-66
to lowest temperature
1000°
0-56
Thermodynamics of the Gas Engine 69
Comparing first the best results of each type, it is evident that
type i is the least perfect as a heat-engine, giving back only 0-29
of the total heat entrusted to it as mechanical work, and rejecting
the rest of the heat. Type 2 is distinctly better, giving a maximum
efficiency of 0-45, or nearly half the heat converted into work.
Type i A, with a heat conversion of o'66, is still better.
It cannot be too constantly kept in mind that it by no means
follows that the best theoretic efficiency will give the best result in
practice. If gained at the expense of great volume or an imprac-
ticable process, it may not be worth so much as a worse cycle
where small volume of cylinder and an easy process make it more
easily attainable. Type i A is at a great disadvantage in the
matter of expansion ; it requires, as has been shown, expansion of
967 and 37-5 volumes respectively, so great that it is practically
out of comparison as a workable cycle with the others. The
other cycles vary in this respect also, but the variation will fall
under the consideration of mechanical efficiency at a later stage.
Type i A is so much out that it was necessary to mention it here.
In type i, the efficiency varies with the temperature of explo-
sion, especially where the expansion is carried to atmosphere ; the
difference, however, is not great, a very large increase of maximum
temperature but slightly increasing the efficiency, 1000° C. giving
0-23, and 1600° C. only 0*29, of heat conversion. When the
expansion is limited to twice the volume at the moment of heat-
ing, the effect of increasing temperature in increasing the efficiency
is almost nil, 1000° C. giving 0-20 efficiency 5 and 1600° C. only
0*22 efficiency, The conclusion to be drawn from the fact is this :
in engines of the Lenoir or Hugon kind, with limited expansion,
the economy is not increased by using high temperatures ; a weak
mixture will give as good an indicated efficiency as a strong one.
With type 2, the maximum efficiency is obtained by expand-
ing to atmospheric pressure, and in this case it is quite independent
of the temperature of combustion; it does not matter whether a great
or small increase of temperature occurs at the pressure of compres-
sion, the efficiency remains the same. That is, whether much heat
be added or little heat, the proportion converted into work de-
pends on one thing only, that is, the amount of compression — the
greater the compression the greater the efficiency of the engine.
?o The Gas Engine
The pressures of compression which have been calculated, are
pressures which have been used for the kind of cycle in practice.
The only limits to increasing compression are the practical ones of
strength of engine and leakage of piston. The difference between
efficiency at 60 Ibs. and 100 Ibs. compression above atmosphere is
considerable, the first giving E = 0*37, the second E = 0*45.
When the expansion is limited to twice the volume existing
before compression the maximum temperature then affects the
efficiency, but not to such an extent as the compression.
Type 3.— This is the best type of all from the point under con-
sideration. The efficiency in the best form of it varies both with
maximum temperature and pressure of compression. At 1600° C.
maximum temperature and compression 60 Ibs. per square inch
above atmosphere, £ = 0-51. At the same maximum tempera-
ture but the higher compression of 100 Ibs. above atmosphere, it
rises. With maximum temperature of 1000° C. for these two
compression pressures the efficiencies are E = 0*47 and E = 0*52.
The best case of this type is not the one occurring in practice, in
fact no compression engine of this kind has ever been much
which expands to atmosphere. Usually expansion is only carried
to the same volume as existed before compression, and there the
efficiency is quite independent of the maximum temperature ; it
is determined by compression solely as in type 2.
For compression 60 Ibs. per square inch above atmosphere it
is 0*37, and for 100 Ibs. per square inch above atmosphere it is
o-45, the difference between types 2 and 3 in this case being,
that type 2 expands its working fluid at the pressure of compres-
sion, which remains constant, and the pressure falls to the pressure
of atmosphere by the movement of the piston doing work ; in
type 3 the heat is added to the working fluid at constant volume,
pressure increasing, then expansion doing work, till volume
before compression is attained. The one acts by increase of the
volume of the working fluid by heat, the other by increase of
pressure of the working fluid by heat. The one engine gives
large volumes, low pressures ; the other small volumes, high
pressures.
In type i A, the change of volume required is so great that its
efficiency cannot be fairly compared with the others.
Thermodynamics of the Gas Engine 7 1
Conclusions. — The best cycle for great efficiency, excluding
type i A, is produced by using compression in the manner of
type 3.
In any cycle with any definite expansion, increase of compression
previous to heating produces increase of the proportion of heat
converted into work. In some cases of compression cycles, increase
of the highest temperature does not increase the efficiency;
it may even diminish it.
There are cases in types 2 and 3 when the efficiency is quite
independent of the maximum temperature, depending solely on
the amount of compression employed.
72 The Gas Engine
CHAPTER IV.
THE CAUSES OF LOSS IN GAS ENGINES.
IN calculating the efficiency of the different kinds of engines, it
has been assumed that the conditions peculiar to each cycle
have been perfectly complied with. In actual engines this is
impossible ; it is therefore necessary to discover in what manner
practice fails in performing the operations required by theory.
The actual engines differ from the ideal ones in several
ways :
1. The working fluid loses heat to the walls enclosing it after
its temperature has been raised to the highest point ;
2. The working fluid often gains heat when entering the
cylinder at a time when it should remain at the lowest tempera-
ture;
3. The supply of heat is never added instantaneously as is re-
quired in some types ;
4. The working fluid does not behave as a perfect gas ; owing
to the complex phenomena of combustion, to some extent its
physical state is changed during the addition of heat ;
5. The admission, transfer and expulsion of the working fluid
are not accomplished without some resistance, wire-drawing during
admission, back-pressure during exhaust.
The first cause of loss is by far the most considerable and will
be considered first.
Loss OF HEAT TO THE CYLINDER AND PISTON.
Although this is the most considerable source of loss in all
gas engines, the stock of information in existence upon the subject
is quite insufficient to justify any attempt to state a general law.
So far as the author is aware, no experiments have yet been made
The Causes of Loss in Gas Engines 73
to determine the rate at which a mass of heated air, at from 1000°
to 1600° C. loses heat to the comparatively cool metal surfaces
which enclose it. That the rate of flow is rapid is quite evident.
Otherwise, it would be impossible to raise steam with the relatively
small heating surfaces generally used in boilers. Before applying
the efficiency values obtained to actual practice it is necessary to
know at what rate a cubic foot of air at about 1600° C. in contact
with metal walls at from 17° C. to 100° C. will lose heat; also to
know how that rate changes with change of temperature and
density. Much is known of the laws of cooling at lower tem-
peratures, but little positive data exist for temperatures so high
as those occurring in the gas engine. A hot gas loses heat to the
colder walls enclosing it mainly by circulation or convection. The
conductivity of gases for heat is very slight, and unless in some
way a large surface of the gas is exposed to the cooling surface,
practically no heat would escape from the working fluid in the short
time during which it is exposed in gas engines. Any arrangement
which favours or hastens convection will therefore increase loss by
increasing the extent of hot gaseous surface exposed to the walls.
The smaller the surface to which a given volume of working fluid
is exposed the less heat will it lose in a given time. So far as
loss of heat is concerned then, the best type of engine is that
which exposes a given volume of working fluid to the smallest
surface in performing its cycle. Suppose that in the three types
the pistons move at the same velocity, then that which requires to
move through the smallest volume, the areas of the pistons being
supposed equal, will take the shortest time to perform its cycle. In
the first engine the piston moves through 27 vols., with the hot air
filling the cylinder; the second, through 3*7 vols.; and the third,
through 2 '4 vols. (see diagrams n, 13 and 15). As the volumes
are proportional to the time taken to perform each cycle the
third type has the best of it, the time of exposure of the hot
working fluid being the least ; the second type is worse than
the first. There is still another circumstance in addition to
surface exposed and time of exposure, that is, the average
temperature of the hot gas which is exposed. If the average
temperature is lower in one type than in another during ex-
posure to a given surface for a certain time, then obviously
74 The Gas Engine
less heat will be lost in the one than in the other. Comparing
the average temperatures it is found, that in the first the tempera-
ture ranges from 1600° C. to 817° C. ; in the second from 1600° C.
to 901° C. ; and in the third from 1600° C. to 510° C. The
third will therefore show a lower average temperature than the
others. Three conditions are requisite in the engine which is to
lose the minimum of heat from its working fluid :
1. In performing its cycle it should expose a given volume of
its working fluid to the least possible cooling surface ;
2. It should expose it for the shortest possible time ;
3. The average temperature during the time of exposure should
be as low as possible —
which conditions are best fulfilled by the third type. In ad-
dition to its advantage in theoretic efficiency it possesses the
further good points in practice of proportionally small cooling
surfaces, short time of exposure, and rapid depression of tempera-
ture due to work done, consequently small loss of heat to the
cylinder and piston.
The diagrams, figs, n, 13 and 15, have been selected from the
others belonging to each type because the pressures, temperatures,
and relative volumes closely correspond with those which would
be best and at the same time readily practicable.
The flow of heat really occurring in the gas engine cylinder
will be discussed when the actual diagrams come under considera-
tion ; meantime, it is sufficient to have proved that the third type
will in practice give results more closely approaching its theory
than the others. If in each case a constant proportion of the
heat supplied were lost to the cylinder and piston, the ratio of the
efficiencies would remain constant, and although it would be im-
possible from present data to predict the actual values, yet
the relative values would be known.
GAIN OF HEAT BY THE WORKING FLUID WHEN ENTERING
THE ENGINE.
In all types of gas engine it is found most economical to keep
the motor cylinders as hot as possible ; they are generally worked
at a temperature close upon the temperature of boiling water.
This is done to diminish the loss of heat from the explosion. It
The Causes of Loss in Gas Engines
75
follows that if the working fluid is introduced at a lower temperature
it becomes heated. In the first type, the charge should be admitted
and remain at the lowest temperature until the moment of explosion,
which is of course impossible if the cylinder is at 100° C. As the
piston itself is hotter than that, it may be supposed that the charge
is heated to that point.
Taking an extreme case and calculating the effect of having
an absolute temperature of 390° for the lower limit, it will be
found that the efficiency is diminished. In case i, type i, where
the expansion is carried to atmosphere with a maximum tem-
perature of 1873° absolute = 1600° C., the value becomes reduced
to 0-23.
With a maximum temperature of 1 2 7 3° absolute = 1 000° C the
efficiency is 0*16.
TYPE I.
Initial temp, of working
fluid
Max. temp.
Efficiency
17° C.
117° C.
17° C.
n7°C.
1600° C.
1600° C.
1000° C.
1000° C.
0-23
0-23
0*16
Here heating, while introducing the charge will always cause
diminution in efficiency, the proportion of loss being greater with
the lower maximum temperature. At 1600° C. the loss is nearly
one-fifth, while at 1000° C. it is close upon one-fourth.
It is very difficult to say whether it is better to work with the
cylinder hot or cold. The constructor finds himself in a dilemma ;
if the cylinder is kept as cold as the surrounding air, then the
hot gases cool more rapidly. If he keeps the cylinder hot to
diminish this, the efficiency falls also. Experiment alone can
decide the question.
In engines of type 2 it is a usual proceeding to leave the
compression cylinder entirely without water-jacketing, under the
impression that heat is thereby saved ; the temperature consequently
rises to very nearly that of compression, and the entering charge
becomes considerably heated before compression. This is especi-
ally the case if the admission area is small, and throttling occurs ; all
76 The Gas Engine
the energy of velocity of the entering gas becomes transformed into
heat. As in the previous case the charge may be considered to rise
to 117° C. before compression.
Where expansion is carried to atmosphere it has been shown
that the efficiency is quite independent of the maximum tempera-
ture, but is determined by one circumstance only — the amount of
the compression. As
F, = i * and t is the temperature absolute before compressing
*c
tc ,, ,, ,, ,, alter „
and as -£ = ( ^ ) ~T , it follows that with a constant ratio between
f \p I
the pressures before and after compression, the ratio of temperature
before and after compressing will also remain constant ; that is,
the efficiency is not in any way affected by heating the working
fluid, provided the same degree of compression is used. Increase
of temperature previous to compression causes a proportional in-
crease of temperature after compressing without in any way disturb-
ing the ratio between them.
This is an important, if in appearance a somewhat paradoxical
fact, and it may be stated in another way :
If an engine receives all its supply of heat at one pressure,
and rejects all its waste heat at another pressure, after falling
from the higher to the lower pressure by expansion doing work,
the efficiency is constant for all maximum temperatures of the
working fluid.
The proportion of heat converted into work is not changed in
any way by increasing the temperature before compressing, and
if only one degree of heat be added after compressing, the same
proportion of that one degree is converted into work, as would be
done with any addition of heat however great.
Where the expansion is not continued enough to reduce the
pressure after heating, to atmosphere, as in the cases of this type
which occur in practice, this is not quite true ; the compression
still remains the most powerful element of efficiency, but heating
before compression produces some change, just as increase of
temperature after compression produces change. The change is
* See p. 57.
The Causes of Loss in Gas Engines 77
not great, and it is always in the direction of improvement with a
limited expansion. If the lower temperature / is increased, the
compression temperature tc increases in proportion, and is ac-
cordingly nearer the maximum temperature. The volume increases
less on heating, so that the effect upon efficiency is the same as if
the expansion had been increased ; the terminal pressure will more
closely approach atmosphere, and therefore come nearer to the
condition of maximum efficiency.
In engines of type 3 the compression and expansion are often
performed in the same cylinder. For this purpose it is necessary
to leave at the end of the cylinder a space into which the charge
is to be compressed. As the piston does not enter this space, a
considerable volume of exhaust gases remains to mix with the fresh
cold charge. Partly from this and partly from the heating effect
of the cylinder and piston, the charge becomes considerably heated
before compression. The temperature of 200° C. is not unusual.
Here the simplest case is that where the expansion is continued
to the same volume as existed before compression. The efficiency
depends solely upon the amount of the compression ; for any
given degree of compression it is constant, whether the addition
of heat at constant volume after compression be great or small.
The efficiency is E=I — as in type 2 (see p. 57) ; and the two
*r
absolute temperatures vary in the same ratio, that is, if the charge
is heated before compression, the temperature after compression will
be increased in the same ratio. The two temperatures will therefore
bear a constant ratio to each other, whatever the initial temperature
may be, provided the compression is constant. Heating the charge
before compression will consequently have no disturbing effect upon
the theoretical efficiency.* %
Where the expansion is carried to atmosphere the case is
different. The diagram (fig. 15) may be considered to be made up
of two parts giving two different efficiencies, the sum of which in
this case is 0-51. In expanding from the compression volume v.
to the original volume v (compression 75 Ibs. per square inch)
* It is here necessary to distinguish between theoretical and practical efficiency.
Heating before compression diminishes efficiency in practice by increasing max-
imum temperature, and therefore loss of heat.
78 The Gas Engine
the total efficiency is 0*37, and from that volume to v and atmos-
pheric pressure, 0*14. The latter portion still obeys the same law
as in a similar case of type i ; so that if the initial temperature at
volume v be supposed 117° C. it will lose efficiency in a similar
way. The temperature 901° C. will still exist at that point of the
expanding line, so that it may be taken as similar to the case
calculated • on p. 75, where 1000° C. is the maximum. The loss
of efficiency there is from 0-23 to 0-16 for an initial temperature
of 117° C., which makes 0*14 become nearly o-io. The total
efficiency would therefore be 0*47 instead of 0*51 without previous
heating.
Efficiency diminishes with increased temperature of working
fluid before compressing, if the expansion is carried to atmosphere,
but does not change where the expansion is limited to the initial
volume.
OTHER CAUSES OF Loss.
The third, fourth, and fifth causes of loss require for their ex-
amination a comparison of the actual diagrams, and a knowledge
of the phenomena of explosion and combustion, and so cannot be
discussed at this stage.
79
CHAPTER V.
COMBUSTION AND EXPLOSION.
IN the preceding chapters the gas engine has been considered
simply as a heat engine using air as its working fluid ; it has been
assumed that in the different cycles, the engineer is able to give
the supply of heat either instantaneously, or slowly, at will ; and
also that he can command temperatures so high as 1000° C. or
1600° C. It is now necessary to study the properties of gaseous
explosive mixtures in'order to understand how far these assump-
tions are true.
ON TRUE EXPLOSIVE MIXTURES.
When an inflammable gas is mixed with oxygen gas in certain
proportions, the mixture is found to be explosive : a flame ap-
proached to even a small volume contained in a vessel open to the
air will produce a sharp detonation. Variation of the proportions
will cause change in the sharpness of the explosion. There is a
point where the mixture is most explosive ; at that point the in-
flammable gas and the oxygen are present in the quantities
requisite for complete combination. After explosion the vessel
will contain the product or products of combustion only, no
inflammable gas remaining unconsumed, or oxygen uncombined,
both having quite disappeared in forming new chemical com-
pounds.
That mixture may be called the true explosive mixture.
Definition. — When an inflammable gas is mixed with oxygen
in the proportion required for the complete combination of both
gases, the mixture formed is the true explosive mixture.
If the chemical formula of an inflammable gas is known, the
volume of oxygen necessary for the true explosive mixture can
8o The Gas Engine
be at once calculated. Elementary substances combine chemi-
cally with each other in certain weights known as the atomic or
combining weights: chemical symbols are always taken as repre-
senting those weights of the elements indicated. In dealing with
inflammable gases used in the gas engine it is convenient to
remember the following symbols and weights :_
Element
Symbol
Combining weight
Oxygen ......
Hydrogen
0
H
N
16
I
*4
Carbon
Sulphur
C
s
12
32
In entering or leaving any compound the elements invariably
enter or leave in weights proportional to those numbers or
multiples of them. Thus hydrogen and oxygen combine with
each other, forming water ; the formula of the compound is
H2O, meaning that 18 parts by weight contain 16 parts of O and
2 parts of H. Similarly when carbon combines with oxygen two
compounds may be formed, according to the conditions, carbonic
oxide or carbonic acid, formulae CO and CO2, the former containing
in 28 parts by weight, 12 parts of carbon and 16 parts of oxygen;
the latter in 44 parts by weight containing 1 2 parts of carbon and
32 parts of oxygen.
The formula of a compound therefore not only indicates its
nature qualitatively, but it also indicates its quantitative composition.
H2O not only tells the nature of water, but it represents 18
parts by weight ; CO means 28 parts by weight of carbonic oxide :
CO2 means 44 parts by weight of carbonic acid. The numbers 1 8,
28 and 44 are know as the molecular weights of the three com-
pounds in question.
When dealing with gases it is more convenient to think in
volumes than in weights. It is easier, for instance, to measure the
proportions of explosive mixtures by volume and to say this mix-
ture contains one cubic inch, one cubic foot or one volume of
inflammable gas to so many cubic inches, feet or volumes of oxygen.
Fortunately there exists a simple relationship between the
volumes of elementary gases and their combining weights, and
Combustion and Explosion 8 1
also between the volumes of compounds and their molecular
weights.
If equal volumes of the elementary gases are weighed, under
similar conditions of temperature and pressure, it is found that
their weights are proportional to the combining weights. Taking
the weight of the hydrogen as i, then the weights of equal
volumes of nitrogen and oxygen are 14 and 16 respectively. If
then it is wished to make a mixture of hydrogen and oxygen gases
in the proportion of 2 parts by weight of the former to 16 parts by
weight of the latter, it is only necessary to take 2 vols. H and
1 vol. O. The law may be stated in two ways, as follows :
Taking hydrogen as unity the specific gravity of the elementary
gases is the same as their combining weights ; or
The combining volumes of the elementary gases are equal.
Instead of troubling to weigh out portions of the gases it is
at once known that one volume of nitrogen weighs 14 parts, the
same volume of hydrogen weighing one part, oxygen 16 parts, and
so on through all the gaseous elements, under the same tempera-
tures and pressures.
Knowing that water is the compound formed by the combus-
tion of hydrogen and oxygen, and that its formula is H2O, it is at
once apparent that the true explosive mixture of these gases is
2 vols. H and i vol. O. By experiment it is found that the volume
of the water produced is less (of course in the gaseous state) than
the volume of the mixed gases before combination.
The measurement requires to be made at a temperature high
enough to keep the steam formed in the gaseous state. Measure
2 vols. H and i vol. O into a strong glass vessel heated to 130° C;
the total is 3 vols. ; fire by the electric spark over mercury. It
will be found that the steam formed when it has cooled to 130° C.
after the explosion, measures 2 vols. It has been found to be
true for all gaseous compounds, that however many volumes of
elementary gases combine to form them the product is always two
volumes. In elementary gases, one volume always contains the
combining weight ; in compound gases, two volumes always con-
tain the molecular weight. Compared with hydrogen, therefore,
the specific gravity of a gaseous compound is always one-half of
the molecular weight.
G
82 The Gas Engine
As before, the law may be stated in two ways :
Taking hydrogen as unity, the specific gravity of a compound
gas is half its molecular weight ; or
The combining volume of a compound gas is always equal to
double that of an elementary gas.
These laws are known as Gay-Lussac's laws, and form part of
the very basis of modern chemistry.
Using them, the true explosive mixtures by volume and the
volumes of the products of the combination can be found for any
gas or mixture of gases, whether elementary or compound.
The inflammable compound gases, used in the gas engine,
forming some of the constituents of coal gas are :
Inflammable gas
Formula
Molecular weight
Molecular vol.
Marsh gas ....
Ethylene ....
Carbonic oxide . C
CH4
C,H4
CO
16
28
28
2
2
2
Applying Gay-Lussac's laws, the oxygen required for true
explosive mixtures and the volumes of the products of combus-
tion are as follows for all the inflammable gases used in the gas
engine : HX> CO2
Steam. Carbonic
acid.
2 vols. hydrogen (H) require i vol. oxygen (O) forming . . 2 vols.
2 vols. marsh gas (CH4) require 4 vols. oxygen (O) forming . 4 vols. 2 vols.
2 vols. ethylene (C2H4) require 6 vols. oxygen (O) forming . 4 vols. 4 vols.
2 vols. carbonic oxide (CO) require i vol. oxygen (O) forming — 2 vols.
2 vols. tetrylene (C4H8) require 12 vols. oxygen (O) forming . 8 vols. 8 vols.
With hydrogen and oxygen 3 volumes before combination
become 2 volumes after combination. CH4 and O, also C2H4 and
O, the volumes of the products of combustion, are equal to the
volumes of mixture. With carbonic oxide and oxygen 3 volumes
before become 2 volumes after combination.
ON INFLAMMABILITY.
Previous to 1817, Sir Humphry Davy made the admirable
researches which led him to the invention of the safety lamp. He
then made experiments upon different explosive mixtures, and
found that under certain conditions they lost the capability of
Combustion and Explosion 83
ignition by the electric spark. True explosive mixtures, he ob-
served, may lose inflammability in two ways ; by the addition of
excess of either ot the gases or of any inert gas such as nitrogen,
and by rarefaction. The hydrogen explosive mixture, if reduced to
one-eighteenth of ordinary atmospheric pressure, cannot be in-
flamed by the spark. Heated to dull redness at this pressure it
will recover its inflammability and the spark will cause combination.
One volume of the mixture to which has been added nine
volumes of oxygen is uninflammable, but if the density is increased
or the temperature raised, it recovers its inflammability.
Eight volumes of hydrogen added, produces the same effect as
the nine volumes of oxygen, but only one volume of marsh gas
or half a volume of ethylene is required. The excess which destroys
inflammability varies with the temperature, increasing with increase
of temperature. Heating the mixture widens the range, both of
dilution with excess or inert gas and reduction of pressure.
The point where inflammability ceases by diluting is very
abrupt and sharply defined. The author has found that a coal
gas which will inflame by the spark in a mixture of i gas and
14 air will not inflame with 15 of air. If the experiment be re-
peated on a warmer day it may inflame with 15 of air, but will not
with 1 6 air. As the proportion is fixed for any given temperature
it will be convenient to call that proportion for any mixture the
' critical proportion.' Any mixture in the critical proportion be-
comes inflammable by a very small increase of temperature or
pressure. The exact limits of dilution temperature and pressure
have yet to be discovered.
Passing from any true explosive mixture by dilution to the
mixture in the critical proportion, the inflammability slowly
diminishes, the explosion becoming less and less violent, till at last
no report whatever is produced, and the progress of the flame (if
a glass tube is used) is easily followed by the eye.
In his great work on gas analysis, Professor Bunsen confirms
Davy's observations in every particular, proving loss of inflam-
mability by dilution and reduction of pressure as well as its
restoration by heating, increase of pressure and slight addition of
the inflammable gas. His work, however, was not published till
1857-
G 2
84 The Gas Engine
ON THE RATE OF FLAME-PROPAGATION.
The sharp explosion of a true explosive mixture is due to the
very rapid rate at which a flame, initiated at one point, travels
through the entire mass and thereby causes the maximum pressure
to be rapidly attained. With a diluted mixture the flame travels
more slowly. Dilution therefore diminishes explosiveness in two
ways — by increasing the time of getting the highest pressure and
also by diminishing the highest pressure which can be got.
Professor Bunsen's experiments are the earliest attempts to
measure the velocity of flame movement in explosive mixtures.
His method is as follows :
The explosive mixture is allowed to burn from a fine orifice of
known diameter, and the rate of the current of the issuing gas
carefully regulated by diminishing the pressure to the point at
which the flame passes back through the orifice and inflames the
explosive mixture below it. This passing back of the flame occurs
when the velocity with which the gaseous mixtures issue from the
orifice is inappreciably less than the velocity with which the in-
flammation of the upper layers of burning gas is propagated to the
lower and unignited layers. Knowing then the volume of mixture
passing through the orifice and its diameter, the rate of flow at
the moment of back ignition is known. It is identical with the rate
of flame propagation through the mixture.
Bunsen made determinations for the true explosive mixtures
of hydrogen and carbonic oxide.
VELOCITY OF FLAME IN TRUE EXPLOSIVE MIXTURES. (Bunsen.}
Hydrogen mixture (2 vols. H and i vol. O). -34 metres per sec.
Carbonic oxide mixture (i vol. CO and i vol. O) . i metre per sec. nearly.
The method is a singularly simple and beautiful one and
answered thoroughly for Professor Bunsen's purpose at the time
he devised it. Several objections, however, may be brought against
it. The mixture in issuing from the jet into the air as flame,
becomes mixed to some extent with the air and so cools down ;
the metal plate also, pierced with the orifice, exercises a great
cooling effect. If the hole were made small enough the flame
could not pass back at all, however much the flow is reduced,,
Combustion and Explosion 85
because the heat would be conducted away so rapidly as to
extinguish the flame. This had been shown by Davy in 1817;
indeed it is the principle of the safety lamp. These causes prob-
ably make Bunsen's velocities too low. MM. Mallard and Le
Chatelier have made velocity determinations by a method designed
to obviate those sources of error.
The explosive mixture is contained in a long tube of considerable
diameter, closed at one end, open to the atmosphere at the other.
At each end a short rubber tube terminates in a cylindrical space
closed by a flexible diaphragm. A light style is fixed upon the
diaphragms. A drum revolves close to each style, both drums
upon the same shaft. A tuning fork, vibrating while the experi-
ment is being made, traces a sinuous line upon the drum and so
the rate of revolution is known. The mixture is ignited at the
open end, and the flame in passing the lateral opening leading to
the first diaphragm ignites the mixture there, and so moves the
style and marks the drum; the arrival of the flame is signalled at
the other end in the same way. The drums revolving together,
the distance between the two style markings measured by the
vibration marks of the tuning fork gives the time taken by the
flame to move between the two points. The numbers got in this
way are the rates of the communication of the flame through the
mixture, back into the tube, while the flame can freely expand to the
air; when both ends are closed the velocity is much greater. Then,
not only does the flame spread from particle to particle of the
explosive mixture at the rate due to contact of the inflamed particles
with the uninflamedones, but the expansion produced by the inflam-
mation projects the flame mechanically into the other part and so
produces an ignition, which does not travel at a uniform rate, but at a
continually accelerating one. In the same way, using the open tube
but firing at the closed end, the expansion of the first portion adds
to the apparent velocity of propagation, and projects the last
portion of the mixture into the atmosphere. The true velocity of
the propagation is the rate at which the flame proceeds from particle
of inflamed mixture to uninflamed particle by simple contact ; the
true velocity depends upon inflammability alone, the rate under
other conditions depends also upon heat evolved, and therefore
movement due to expansion, mechanical disturbance of the unig-
86 The Gas Engine
nited by the projection of the ignited portion into its midst. These
conditions may vary much ; the inflammability remains constant.
Mallard and Le Chatelier's results for the true velocity of pro-
pagations are :
VELOCITY OF FLAME IN TRUE EXPLOSIVE MIXTURES.
(Mallard and Le Chatelier. )
per sec.
Hydrogen mixture (2 vols. H and i vol. O) . . .20 metres.
Carbonic oxide (2 vols. CO and i vol. O) . . . 2*2 ,,
Bunsen's rate for hydrogen mixture seems to have been too
great, and for carbonic oxide mixture too little. The rate for a true
and very explosive mixture such as hydrogen is liable to be inac-
curately determined, as temperature variation makes a great
change, and it is difficult even with Mallard and Le Chatelier's
method to obtain concordant experiments. With less inflammable
mixtures the difficulty disappears. As true explosive mixtures are
never used in the gas engine, their properties concern the engineer
only as a preliminary to the study of diluted mixtures. The most
explosive mixture which can be made with air contains a large
volume of nitrogen inevitably present as diluent.
The following are some of their results with diluted mixtures,
which are stated to be correct within 10 per cent, error of experi-
ment :
VELOCITY OF FLAME IN DILUTED MIXTURES. (Mallard and Le Chatelier.}
per sec.
i vol. hydrogen mixture + \ vol. oxygen . . .17*3 metres.
,, ,, +i vol. oxygen . . .10 ,,
,, ,, + i vol. hydrogen . . .18 ,,
,, ,, +i vol. hydrogen . . 11*9 ,,
,, +2 vols. hydrogen . . . 8'i ,,
These rates show that the true explosive mixture of hydrogen
and oxygen when diluted with its own volume of oxygen falls from
20 metres per second to 10 metres, that is, it becomes one-half
as inflammable ; when its own volume of hydrogen is the diluent,
the velocity only falls to 11*9 metres per second. Hydrogen there-
fore has less effect in diminishing inflammability than oxygen.
Remembering the fact that the atmosphere contains one- fifth
of its volume of oxygen, the remaining four-fifths being nearly all
nitrogen, it is easy to get the proportions for the strongest explosive
Combustion and Explosion 87
mixture possible with air. Two volumes hydrogen require i volume
oxygen, and therefore 5 volumes air. The strongest possible mixture
with air is two-sevenths hydrogen, five-sevenths air. The following
experiments are for hydrogen and air in different proportions :
VELOCITY OF FLAME IN DILUTED MIXTURES. (Mallard and Le Chatclier.)
per sec
Mixture, vol. H and 4 vols. air . . . .2 metres.
, H and 3 vols. air . . . 2*8
, H and 2^ vols. air . . . . 3-4
, H and if vols. air . . . . 4'i
, H and i£ vols. air . . . . 4-4
, H and i vol. air .... 3-8
, H and ^ vol. air .... 2*3
Very strangely the velocity is greatest when there is an excess of
hydrogen present. To get just enough of oxygen for complete burn-
ing, i volume H requires 2\ volumes air, which would be naturally
supposed to be the most inflammable mixture, as it gives out the
greatest heat, but for some reason it is not. When the hydrogen
is increased beyond i volume H to \\ volumes air the velocity
again falls off. A determination for coal gas and air gave i volume
gas, 5 volumes air a velocity of roi metres per second, and
i volume gas, 6 volumes air 0*285 metres per second. With coal
gas also the maximum velocity is got with the gas slightly in excess.
So far, these rates of ignition or inflammation are measures of
inflammability, and are the rates for constant pressure; the rates for
constant volume are very different, and the problem is a more
complex one. Inflaming at the closed end of the tube, they found
that even very dilute mixtures gave a sharp explosion, and in the
case of hydrogen true explosive mixture, the velocity became 1000
metres per second instead of 20. With hydrogen and air 300
metres per second were obtained.
MM. Berthelot and Vieille have proved that under certain cor.
ditions even greater velocities than these are possible. The con-
ditions, however, are abnormal, and the generation of M, Berthelot's
explosive wave is exceedingly undesirable in a gas engine. It is
generated by inflaming a considerable portion of the mixture at
once, and so causing the transmission of a shock from molecule
to molecule of the uninflamed mixture: this shock causes an
ignition velocity nearly as rapid as the actual mean velocity of
movement of the gaseous molecules at the high temperatures of
88 The Gas Engine
combustion. The difference between this almost instantaneous
detonation and the ordinary flame propagation may be compared
to similar differences in the explosion of gun cotton discovered
by Sir Frederic Abel. Gun cotton lying loosely, and open to the
air, will burn harmlessly if ignited by a flame; indeed, a consider-
able portion may be laid upon the open hand and ignited by a
flame without the smallest danger. The same quantity in the
same position, if fired by a percussive detonator, will occasion
the most violent explosion, the nature of the shock given to the
gun cotton by the detonator causing a transmission of the kind of
vibration necessary to cause its almost instantaneous resolution
into its component gases.
The explosive wave in gases seems to originate in like con-
ditions. Its velocity for the true explosive mixture of hydrogen
and oxygen is 2841 metres per second, and for carbonic oxide
mixture, 1089 metres per second. The velocity is independent of
pressure between half an atmosphere and one and a half atmo-
sphere. It is independent, too, of the diameter of the tube used,
within considerable limits, or of the material of the tube, rubber
and lead tubes giving similar results. Diluting the mixtures di-
minishes, and heating increases it. The experiments are very
interesting and important, from a physicist's standpoint, but,
fortunately for the inventor dealing with gas engines, the explosive
wave is not easily generated in a gas engine cylinder; if it were,
it would be impossible to run the engines without shock and
hammering.
The velocity which really concerns the engineer is that due
to inflammability, and expansion produced by inflaming — the
velocity, in fact, with which the inflammation spreads through a
closed vessel. As it cannot be discussed without considering
other matters — heat evolved by combustion, and temperatures and
pressures produced — it will be advisable first to give the heat
evolved by combustion, and then devote a complete chapter to
explosion in a closed vessel.
HEAT EVOLVED BY COMBUSTION.
Careful experiments upon the heat evolved by the combustion
of gases in oxygen have been made by Favre and Silberman, and
Combustion and Explosion 89
also by Professor Andrews. The physicists first named burned
the gases at constant pressure in a specially devised calorimeter.
Professor Andrews mixed the gases in a thin spherical copper
vessel, closed it, and exploded by the spark: the vessel being sur-
rounded by water gave up its heat to the water, the weight of which
being known, the rise of temperature gave the heat evolved.
Quantities of heat are measured by taking water as the unit.
In this work, a heat unit always means the amount of heat neces-
sary to raise unit weight of water through i° C.
Taking an average of Favre and Silberman and Andre ws's
results, the inflammable gases used in gas engines evolve upon com-
plete combustion the following amounts of heat :
Heat units.
Unit weight of hydrogen completely burned to H2O evolves . . 34,170
Unit weight of carbon completely burned to CO2 evolves . . . 8,000
Unit weight of carbonic oxide completely burned to CO2 evolves . 2,400
Unit weight of marsh gas completely burned to CO2 and H.,O evolves 13,080
Unit weight of ethylene completely burned to CO2 and H2O evolves 11,900
That is, one pound weight of hydrogen burned completely to
water will evolve as much heat as would raise 34,170 Ibs. of water
through i° C., or the converse. One pound of carbon in burning
to carbonic acid evolves as much heat as would raise 8,000 Ibs. of
water through i° C. These numbers give the amount or quantity
of heat evolved. The intensity or temperature of the combustion
may be calculated on the assumption that the whole heat is evolved
under such conditions that no heat is lost, or is applied to any-
thing else but the products of combustion. To make the calcu-
lation it is necessary to know the specific heat of the products.
The amount of heat required to heat unit weight of water
through one degree is i heat unit, the specific heat of any other
body is the number of heat units required to heat unit weight of the
body through one degree. Gases have two different specific heats
depending upon whether heat is applied while the gas is kept at con-
stant volume, or at constant pressure; both are required in dealing
with gas engine problems. The specific heat at constant volume
is sometimes known as the true specific heat; in taking the specific
heat at constant pressure the gas necessarily expands, and so does
work on the external air; this specific heat is therefore greater
than the former by the amount of work done. For the gases used
9<D The Gas Engine
in the gas engine the two values are as follows. The ratio be-
tween the two is also given, as it is frequently required in efficiency
calculations. The experimental numbers are Regnault's, the
calculated specific heat at constant volume, Clausius.
SPECIFIC HEATS OF GASES.
(For equal weights. Water = i.)
Sp. heat at
Sp. heat at
Sp. heat con. pres.
constant pressure
constant volume
Sp. heat con. vol.
Air
0-237
0*168
•413
Oxygen
0*217
0-155
•403
Nitrogen
0-244
0*173
•409
Hydrogen
3-409
2*406
-417
Marsh gas
0-593
0-467
—
Ethylene
0-404
0-332
•144
Carbonic oxide
0-245
0-173
•416
Steam .
0*480
0-369
•302
Carbonic acid
0*216
0-171
1
It is convenient to remember that the specific heats of com-
bining or atomic weights of the elements are equal — Dulong and
Petit's law. To this law there are few exceptions, and the per-
manent elementary gases, oxygen, nitrogen, and hydrogen, obey it
almost absolutely. As equal volumes of these gases represent the
combining weights, it follows that equal volumes of these gases
have the same specific heat. Taking the specific heat of air as
the unit, the specific heat of hydrogen and oxygen gases is also
unity. The compound gases do not obey the law so closely.
The calculation of temperature of combustion can now be made.
The amount of heat evolved from unit weight of a combustible is
usually said to measure its calorific power, that amount divided by
the specific heat of the products of the combustion is said to be the
measure of its calorific intensity. The calorific intensity is indeed
the theoretical temperature of the combustion : taking hydrogen
first, unit weight evolves 34, 1 70 heat units. But the water formed
weighs 9 units (from formula H2O), and if its specific heat in the
gaseous state were unity, the supposed maximum temperature of
combustion would be _ = 3796*6. But the specific heat is
Combustion and Explosion 9 1
less than unity ; therefore the theoretical maximum will be greater.
It is — -—= 79097. For certain reasons to be considered
9 x 0-480
later, no such enormous temperatures are ever attained by com-
bustion. In the above calculation the latent heat of steam should
first have been deducted, as it is included in the total heat evolved
as measured by the calorimeter : it is 537 heat units. 34,170 — 537
gives the total heat available for increasing the temperature, the
amended calculation is M1Z5L ~ 537 = 7 785 -4, still an exceedingly
high temperature.
Calculating the heat evolved by burning carbon in the same
•way, but omitting any deduction for the latent heat of carbonic
acid (it does not affect the calorimeter, as it does not condense),
the theoretical temperature produced by burning in oxygen is
still higher, being 10,174° C. Burning in air the theoretical
temperatures are lower as the nitrogen present acts as a diluent,
and must necessarily be heated to the same temperature as the
products of the combustion. They are given as follows in ' Watts'
Dictionary.'
Temperature produced
Calorific power „ --- • — --- v
In oxygen In air
Carbon .... 8080 10174° C. 2710° C.
. Hydrogen .... 34462 6930° C. 2741° C.
These are the supposed temperatures burning in the open
atmosphere, and therefore at constant pressure, the gases expand-
ing doing work upon the air. At constant volume, that is,
burning in a closed vessel so that the volume cannot increase but
only the pressure, the temperature should be greater as the
.specific heat at constant volume is less. Allowing for that, the
numbers become
THEORETICAL TEMPS. OF COMBUSTION AT CONSTANT VOLUME.
Temperature produced
In oxygen In air
Carbon .... 12820
Hydrogen .... 9010 4119
Such temperatures have never been produced by combustion,
92 The Gas Engine
for many reasons, of which all save the most potent have been
discussed by the earlier writers on heat. This is Dissociation.
DISSOCIATION.
Most chemical combinations, while in the act of formation
from their constituent elements, evolve heat, and as a general
rule, the greater the heat evolved the more stable is the com-
pound formed. The compound after formation may generally be
decomposed by heating to a high enough temperature, heat being
one of the most powerful splitting up agencies known to the chemist.
The nature of the decomposition varies with the compound. In
many cases the process is irreversible, that is, although heating up
will cause decomposition, cooling down again, however slowly,
will not cause recombination. In some compounds, however, under
certain conditions the process is reversible, and recombination
occurs on slow cooling.
Definition. — Dissociation may be defined as a chemical
decomposition by the agency of heat, occurring under such con-
ditions that upon lowering, the temperature the constituents
recombine.
Groves found long ago that water begins to split up into
oxygen and hydrogen gases at temperatures low compared to that
produced by combustion. Deville made a careful study of the
phenomena, and found that decomposition commences at 960° to
1000° C. and proceeds to a limited extent : raising the temperature
to 1200° C. increases it, but a limit is reached. The amount of
decomposition depending upon the temperature, for each tempe-
rature there is a certain proportion between the amount of steam
and the amount of free oxygen and hydrogen gases present. If
the temperature is increased, the proportion of free gases also
increases : if temperature is diminished, the proportion of free
gases diminishes. If the temperature be raised beyond a certain
intensity, the water is completely decomposed : if lowered beyond
a certain temperature, complete combination results. The same
thing happens with carbonic acid, the temperature of decomposition
is lower.
It is quite evident, then, that at the highest temperatures pro-
Combustion and Explosion 93
duced by combustion, the product cannot exist in the state of
complete combination. It will be mixed to a certain extent with
the free constituents which cannot combine further until the tem-
perature falls; as the temperature falls, combustion will continue
till all the free gases are combined. The subject, from its nature,
is a difficult one in experiment, and accordingly different observers
do not quite agree upon temperatures and percentages of dissocia-
tion, but all are agreed that dissociation places a rigid barrier in
the way of combustion at high temperatures, and prevents the
-attainment of temperatures, by combustion, which are otherwise
quite possible. With no dissociation, hydrogen burning in oxygen
should be able under favourable circumstances to give a tempera-
ture of over 6000° C, as has been shown. Deville's experiments
upon the temperature of the oxyhydrogen flame, at constant
pressure of the atmosphere, gave under 2500° C. The estimate
was made by melting platinum in a lime crucible, with the oxy-
hydrogen flame playing upon the platinum, the crucible being
well protected against loss of heat by lime blocks, so that the
platinum could really attain the temperature of the flame; when
at the highest temperature, the molten platinum was rapidly
poured into a weighed calorimeter, and the rise in temperature
noted. From this was calculated the temperature of the platinum.
The experiment was dangerous and inaccurate, but it is the only
serious attempt which has been made to determine the temperature
of the oxyhydrogen flame at constant pressure.
The highest temperature produced by hydrogen burning in
oxygen has been determined by Bunsen, and also Mallard and
Le Chatelier, for combustion at constant volume, that is, ex-
plosion.
As the theoretic calculation shows, with no dissociation a
temperature of 9000° C. is possible. The highest maximum it
is possible to assume from Bunsen's experiments is 3800° C. ;
from Mallard and Le Chatelier's, 3500° C. The two sets of ex-
periments are concordant. It is true the latter physicists do not
attribute the difference wholly to dissociation, but they agree that
part is due to this cause; and that there is an enormous difference
between heat temperature actually got and that which should be
possible if no limit existed all are agreed. With air, Bunsen's
94 The Gas Engine
figures show a maximum of about 2000° C., Mallard and Le
Chatelier say 1830° C.; the present writer has also made experi-
ments with hydrogen in air, and finds the highest possible tem-
perature to be 1900° C. The calculated maximum is 4119° C.
The difference is not so great as with the true explosive mixture,
which is to be expected, but all experiments agree in proving that
there is a considerable difference.
95
CHAPTER VI.
EXPLOSION IN A CLOSED VESSEL.
THE value of any inflammable gas for the production of power
by explosion, can be determined apart altogether from theoretical
considerations by direct experiment. It is evident that the gas
which for a given volume causes the greatest increase in pressure,
will give the greatest power for every cubic foot used, provided
that the pressure does not fall so suddenly that it is gone before it
can be utilised by the piston.
Two qualities will be possessed by the best explosive mixture :
(i) greatest pressure per unit volume of gas: (2) longest time of
maximum pressure when exposed to cooling.
In the gas engine itself the conditions are so complex that the
problem is best studied in the first instance under simplified con-
ditions. The author has made a set of experiments upon many
samples of coal gas mixed with air in varying proportions, to find
the pressures produced, and the duration of those pressures;
igniting mixtures at atmospheric pressures and temperature, and
also at higher temperature and initial pressures. He has made
some experiments upon pure hydrogen and air mixtures in the
same apparatus for comparison.
The experimental apparatus is shown at fig. 19. It consists of
a closed cylindrical vessel 7 inches diameter and 8£ inches long,
internal measurement, and therefore of 317 cubic inches capacity.
It is truly bored, and the end covers turned so that the internal
surface is similar to that of an engine cylinder ; the covers are
bolted strongly so as to withstand high pressures. Upon the
upper cover is placed a Richards indicator, in which the reci-
procating drum has been replaced by a revolving one; the rate of re-
volution is adjusted by a small fan, a weight and gear giving the power.
96 The Gas Engine
The cylinder is filled with the explosive mixture to be tested;
the drum is set revolving, the pencil of the indicator pressed
gently against it, and the electric spark is passed between the
points placed at the bottom of the space. The drum is enamelled
and the pencil is a black-lead one. The pressure of the explo-
REVOLVING DRUM
WEIGHT
FlG. 19. — Clerk Explosion Apparatus.
sion acts upon the indicator piston, and a line is traced upon the
drum, which shows the rise and fall of pressure. The rising line
traces the progress of the explosion ; the falling line the progress
of the loss of pressure by cooling. The rate of the revolution of
the drum being known, the interval of time elapsing between any
two points of the explosion or cooling curve is also known. That
is, the curve shows the maximum pressure attained, the time of
attaining it, and the time of cooling. Line b on fig. 20 is a fac-
Explosion in a Closed Vessel
simile of the curve produced by the explosion of a mixture con-
taining i vol. hydrogen and 4 vols. air. Each revolution of the
drum was accomplished in 0-33 sec., so that each tenth of a revolu-
tion takes 0-033 sec- ^ne vertical
divisions give time; the horizontal,
pressures. In this experiment the
maximum pressure produced by the
explosion is 68 Ibs. per square inch
above atmosphere, and it is attained
in 0*026 second. Compared with
the rate of increase the subsequent
fall is very slow. The rise occurs in
0-026 second; the fall to atmo-
sphere again takes 1*5 second, or
nearly sixty times the other. It is
in fact an indicator diagram from an
explosion where the volume is con-
stant, the motor piston being absent,
and the only cause of loss of pres-
sure is cooling by the enclosing
walls. The exact composition of
the mixture, its uniform admixture,
the temperature and pressure before
ignition, are all accurately known.
After studying explosions under
these known conditions, it becomes
easier to understand what occurs
under more complex conditions,
where the moving piston makes the
cooling surface change, and where the
expansion doing work also requires
consideration. As the rapidity
of the increase of pressure measures
the explosiveness of a mixture, the
time occupied from the commence- MDU! .bs }3d .
ment of increase to maximum pres-
sure will be called the time of explosion. The explosion is com-
plete when maximum pressure is attained. It does not follow from
The Gas Engine
ocJuuutjcJu
°i>°loCV%
"
Explosion in a Closed Vessel
99
this that the combustion is complete; that is another matter. The
explosion arises from the rapid spreading of the flame throughout the
whole mass of the mixture, which may be called the inflammation of
the mixture. More or less rapid inflammation means more or
less explosive effect, but not complete combustion. The complete
burning of the gases present does not occur till long after com-
plete inflammation.
The terms combustion, explosion, and inflammation will be used
in this sense alone :
Combustion, burning ; complete combustion, the complete
burning of the carbon of the combustible gas to carbonic acid, and
the hydrogen to water. So long as any portion of the combustible
remains uncombined with oxygen the combustion is incomplete.
Complete explosion, the attainment of maximum pressure.
Time of explosion; the time elapsing between beginning of
increase and maximum pressure.
Complete inflammation, the complete spreading of the flame
throughout the mass of the mixture.
Confusion has arisen through the indifferent use of these terms,
which are really distinct and are not synonymous.
With mixtures made with Glasgow coal gas the author has
obtained the following maximum pressures and times of explosion.
EXPLOSION IN A CLOSED VESSEL. (Clerk.}
Mixtures of air and Glasgow coal gas.
Temp, before explosion . .... . . 18° C.
Pressure before explosion ...... . . atmospheric.
Mixture
Max. press, above atmos.
in pounds per sq. in.
Time of explosion
Gas.
Air.
I vol.
13 vols.
52
0-28 sec.
i vol.
ii vols.
63
o'i8 sec.
i vol.
9 vols.
69
0-13 sec.
i vol.
7 vols.
89
o'oy sec.
i vol.
5 vols.
96
0*05 sec.
The highest pressure which any mixture or coal gas and air
is capable of producing without compression is only 96 Ibs. per
sq. in. above atmosphere and the most rapid increase is not more
rapid than always occurs in a steam cylinder at admission. Many
H 2
IOO
The Gas Engine
are still prejudiced against gas, compared with steam, because of
the so-called explosive effect, and the fear that gas explosions
may occasion pressures quite beyond control, like solid explosives.
The fear is quite unfounded ; the pressure produced by the
strongest possible mixture of coal gas and air is strictly limited
by the pressure before ignition,and can always be accurately known;
and so provided for by a proper margin of safety in the cylinders
and other parts subject to it.
The most dilute mixture of air and Glasgow gas which can be
ignited at atmospheric pressure and temperature contains ^ of
its volume of gas, and the pressure produced is 52 Ibs. above
atmosphere. The time of explosion is 0*28 second; so slow is
the rise that it cannot with justice be termed an explosion. It is
too slow to be of any use in an engine running at any reasonable
speed ; the stroke would be almost complete before the pressure
had risen. The mixture containing \ of its volume of gas is that
with just enough oxygen to burn the gas. It is anomalous that
the highest pressure is given with excess of coal gas. The rate of
ignition also is greatest with that mixture. This agrees with the
results obtained by Mallard and Le Chatelier, excess of hydrogen
giving the highest rate of inflammation.
Similar experiments were made with air and Oldham coal gas,
EXPLOSION IN A CLOSED VESSEL. (Clerk.}
Mixtures of air and Oldham coal gas.
Temp, before explosion 17° C.
Pressure before explosion atmospheric.
Mixture
Max. press, above atmos.
in pounds per sq. in.
Time of explosion
Gas.
Air.
vol.
14 vols.
40
0-45 sec.
vol.
13 vols.
Si'S
0-31 sec.
vol.
12 VOls.
60
0-24 sec.
vol.
ii vols.
61
OT7 sec.
vol.
9 vols.
78
0-08 sec.
vol.
7 vols.
87
o-o6 sec.
vol. 6 vols.
90
o'04 sec.
vol.
5 vols.
91
o'o55 sec.
vol.
4 vols.
80
o'i6 sec.
The highest pressure in this case is 91 Ibs. per square inch
Explosion in a Closed Vessel
101
above atmosphere, but the most rapid explosion* isvo*o4*' second- '
and 90 Ibs. pressure, a little less pressure tha^'is given by^GJasgow. *
gas but a slightly more rapid ignition. The mixturefe'Sufe* evidently'
more inflammable, as the critical mixture is -fa volume of gas
instead of y1^ as with Glasgow gas. Although repeatedly tried,
a mixture of i volume gas 15 volumes air failed to inflame with
the spark.
Hydrogen and air mixtures were also tested as follows :
EXPLOSION IN A CLOSED VESSEL. (Clerk.}
Mixtures of air and hydrogen.
Temp, before explosion 16° C.
Pressure before explosion . ' atmospheric.
Mixture
Max. press, above atmos.
in pounds per sq. in.
Time of explosion
Hyd.
I vol.
I vol.
2 VOls.
Air.
6 vols.
4 vols.
5 vols.
41
68
80
.,
0-15 sec.
o'o26 sec.
o'oi sec.
The inferiority of hydrogen to coal gas, volume for volume, is
very evident ; the highest pressure is only 80 Ibs. above atmosphere,
and the mixture requires f of its volume of hydrogen to give it,
while coal gas gives the same pressure with about -^ volume. The
hydrogen mixture, too, ignites so rapidly that it would occasion
shock in practice, the strongest mixture having an explosion time
of one-hundredth of a second. With gas the most rapid is four-
hundredths of a second.
THE BEST MIXTURE FOR USE IN NON-COMPRESSION ENGINES.
From these tables can be ascertained the best gas and the best
mixture for use in non-compression engines with cylinders kept
cold. Take first Glasgow gas, and determine which mixture gives
the best result.
(i) Power of producing pressure.
Suppose one cubic inch of Glasgow coal gas to be used in each of
the five mixtures, whose maximum pressures and times of explo-
sion are given in the table on p. 99, the mixtures would measure
IO2 The Gas Engine
respectively 14? i1^' 10, 8, and 6 cubic inches. Let them be placed
;frv;tiylmder3 of 14, 12-, 10, 8 and 6 square inches piston area ; the
piston will IH- each case be raised one inch from the bottom of its
cylinder. If the pressures upon the piston were the same, equal
movements of piston would give equal power ; if therefore the
mixtures gave equally good results the maximum pressure multiplied
by the piston area will in all cases be the same.
Multiplying 14, 12, 10, 8 and 6 by their corresponding pres-
sures 52, 63, 69, 89, and 96 respectively, the products are 728,
756, 690, 712, and 576. These numbers are the pressures in
pounds which each mixture is capable of producing with one
cubic inch of Glasgow coal gas, cylinders of such area being used
that the depth of mixture is in every case one inch.
Proportion of Glasgow gas in mixture -^, •£%• TO» i> £•
Pressure produced upon pistons by j " ds
one cubic inch
The best mixture is seen at a glance ; it is that containing
one-twelfth of gas. The pressure produced by one cubic inch of
gas is at its highest value 756 pounds, in a cylinder of 12 inches
piston area, and containing 12 cubic inches of mixture.
In modern gas engines the time taken by the piston to make
the working part of its stroke is generally about one- fifth of a
second. If the pressure in one mixture has fallen more, proportion-
ally in that time, then although it may give the highest maximum,
it may lose too rapidly to give the highest mean pressure. To find
this cooling effect, find the pressure to which each mixture falls
at the end of 0*2 second after maximum pressure ; it is in the
different cases :
Mixture containing gas . . . -jV T*> TO» i> «•
Time after beginning explosion (o«a . 8> Q> S£c
sec. after max. pressure)
Pressure in Ibs. per sq. in . . .43, 48, 47, 55, 57.
Press, respectively by 14, 12, 10, 8, , ^ ^ ^
and 6 . . . . '
The lower row expresses the relative pressures still remaining
after allowing each explosion to cool for one- fifth of a second
from complete explosion ; they express the resistance to cooling
possessed by the mixtures. It is evident at once that the
Explosion in a Closed Vessel 103
strongest mixtures cool most rapidly ; a higher temperature being
produced, more of the heat of the explosion is lost in a given time.
(2) Power of producing pressure and resisting cooling.
To find the best mixture for producing pressure and resisting
cooling, those numbers are to be added to the corresponding ones
for maximum pressure :
Proportion of Glasgow gas in mixture JT> ^, •£$, i, i.
Pressure produced upon pistons by^ 8 fi fi
one cubic inch gas . . J '
Pressure remaining upon pistons o'2 , 6o2 g
sec. after complete explosion . )
Mean pressure . . . . 665, 666, 580, 576, 459.
The mean of the two sets gives numbers expressing the
relative values of the mixture for producing pressure, and at the
same time resisting cooling. The two weakest mixtures are best
in both respects, the low result given by the strongest mixture is
due to the fact that excess of gas is present and it remains unburned,
it proves how easily the consumption of an engine may be increased
by even a slight excess of gas in the mixture.
The two best mixtures ignite too slowly, but in the actual
engine that is easily controlled, as will be explained later.
The best mixtures are i vol. gas 13 volumes air, and i vol.
gas ii volumes air. With more gas the economy will rapidly
diminish.
The experiments with Oldham gas treated in the same way
give the following results :
Proportion of Oldham gas in )
mixture . . . ) TS| TT> T*' TS. io> *. 7. e> if-
Pressure produced upon pistons ) ,
,- 600, 721, 780, 732, 780, 606, 630, 546, 400.
by one cubic inch gas .
Pressure remaining upon pistons \
o'2 sec. after complete explo- [ 31, 4o, 4 . 44- 44> 47« 52> 5°« 4&
sion per sq. inch j
Pressure per piston . . . 465. 560, 546, 528, 440, 376, 364, 300, 230.
Mean pressure upon piston . . 532, 640, 663, 630, 610, 536, 497, 423, 315.
Here, too, the best mixture lies between one-twelfth and one-
fourteenth of gas ; with less and more gas the result becomes worse
and worse. Glasgow and Oldham gases seem to be very nearly
equal in value per cubic foot for the production of power, as the
IO4 The Gas Engine
pressure produced from one cubic inch in the best mixture of
each is very similar. The average pressures during 0-2 second
from complete explosion are exceedingly close, Glasgow gas
mixture containing one-twelfth gas giving 666 Ibs. pressure per
cubic inch of gas, and Oldham gas for the same mixture and the
same quantity giving 630 Ibs. : Glasgow gas one-fourteenth mixture
665 Ibs. pressure, Oldham gas 640 Ibs. The hydrogen experiments
give as follows :
Proportion of hydrogen gas in mixture . }, \, f .
Pressure produced upon pistons by one ^ 2g ^go
cubic inch hydrogen . . . . >
Pressure remaining upon pistons o~2\
sec. after complete explosion per sq. J- 35, 39, 40.
inch )
Pressure per piston . . 245, 195, 140.
Mean pressure upon piston . . . 266, 267, 210.
The best mixture with i cubic inch of hydrogen only gives a
pressure of 267 Ibs. available for 0-2 second, so that its capacity
for producing power, compared with Glasgow and Oldham gas, is
as 267 is to 665 and 640 respectively. To produce equal power
with Glasgow gas nearly two-and-a-half times its volume of hydrogen
is required. The idea is very prevalent among inventors that if
pure hydrogen and air could be used, greater power and economy
would be obtained ; these experiments prove the fallacy of the
notion. Hydrogen is the very worst gas which could be used in
the cylinder of a gas engine, it is useful in conferring inflamma-
bility upon dilute mixtures of other gases, but when present in
large quantity in coal gas it diminishes its value per cubic foot for
power.
PRESSURES PRODUCED IF NO Loss OR SUPPRESSION
OF HEAT EXISTED.
From the fact already mentioned in the last chapter, that the
theoretical temperatures of combustion are never attained in
reality, it will naturally be expected that the pressures produced
by explosions in closed vessels will also fall short of theory.
This is found to be the case. It has been observed by every
experimenter upon the subject, beginning with Him in 1861,
who determined the pressures produced by the explosion of coal
Explosion in a Closed Vessel 105
gas and air, and hydrogen and air. He used two explosion vessels
of 3 and 36 litres capacity ; they were copper cylinders with dia-
meters equal to their length. He used a Bourdon spring mano-
meter to register the pressure. He states that :
(1) With 10 per cent, hydrogen introduced the results were :
according to experiment, 3*25 atmospheres ; according to calcu-
lation, 5 -8 atmospheres.
(2) With 20 per cent, of hydrogen, the results were : according
to experiment, 7 atmospheres, which is very much below the cal-
culation.
(3) With 10 per cent, of lighting gas introduced the results
were : according to experiment, 5 atmospheres, i.e. much more
than with the introduction of an equal volume of pure hydrogen.
He notices especially the low pressure produced by hydrogen
as compared with lighting gases, but observes truly that this should
not excite surprise — although the heat value of hydrogen is great,
yet it is so when compared with equal weights of other substances —
and that coal gas being four or five times as heavy as hydrogen,
quantity is balanced against quality ; therefore volume for volume
it gives out more heat.
He considers that there is no difficulty in explaining the very
considerable difference found between calculation and experiment,
as the metal sides are at so low a temperature compared with the
explosion, that the heat is rapidly conducted away, and the
attainment of the highest temperature is impossible. Bunsen, in
his experiments, observed the same difference, and so later did
Mallard and Le Chatelier. The author's experiments fully
confirm the accuracy of those observers. In no case, whether
with weak or strong mixtures of coal gas and air, or hydrogen
and air, is the pressure produced which should follow the com-
plete evolution of heat.
Thus, with hydrogen mixtures (Clerk's experiments) :
Per sq. in.
i vol. H 6 vols. air gives by experiment . , 41 Ibs. above atmosphere.
The calculated pressure is . . . .88-3
1 vol. H 4 vols. air experiment gives ... 68
Calculated pressure is 124
2 vols. H 5 vols. air experiment gives . . 80
Calculated pressure is . . . . . 176
IO6 The Gas Engine
Without exception the actual pressure falls far short of the
calculated pressure ; in some manner the heat is suppressed or
lost. That the difference cannot altogether be accounted for by
loss of heat is easily proved ; the fall of pressure is so slow from
the maximum that it is impossible that any considerable proportion
of heat can be lost in the short time of explosion. If so large a
proportion were lost on the rising curve, it could not fail to show
upon the falling curve ; it would fall in fact as quickly as it rose.
Again, the increase of pressure would be less in a small than in a
large vessel, as the small vessel exposes the larger surface pro-
portionally to the gas present. It is found that this is not so.
Bunsen used a vessel of a few cubic centimetres capacity, and got
with carbonic oxide and oxygen true explosive mixture 10*2 atmo-
spheres maximum pressure ; Berthelot with a vessel 4000 cb. c.
capacity got 10*1 atmospheres ; with hydrogen true explosive
mixture Bunsen 9-5 atmospheres, Berthelot, 9-9 atmospheres. All
the difference, therefore, cannot be accounted for by loss before
complete explosion.
Mixtures of air and coal gas give similar results.
The following are the observed and calculated pressures for
Oldham coal gas. (Clerk's experiments.)
Per sq. in.
i vol. gas 14 vols. air, experiment gives . . 40 Ibs. above atmosphere
Calculated pressure is . . . . . 89-5
i vol. gas 13 vols. air, experiment gives . . 51-5
Calculated pressure is 96
i vol. gas 12 vols. air, experiment gives . .60 ,,
Calculated pressure is . . . . . 103
i vol. gas ii vols. air, experiment gives . . 61
Calculated pressure is . . . . .112
i vol. gas 9 vols. air, experiment gives . .78
Calculated pressure is . . . . . 134 ,,
i vol. gas 7 vols. air, experiment gives . .87 ,,
Calculated pressure is 168 ,,
i vol. gas 6 vols. air, experiment gives . . 90 '
Calculated pressure is . . . . . 192 ,,
The results with Glasgow gas are so similar that it is unneces-
sary to give a table ; in no case does the maximum pressure
account for much more than one-half of the total heat pre-
sent. As all of the deficit cannot have disappeared previous
to complete explosion, it follows that the gases are still burning
on the falling curve, that is, the falling curve does not truly
Explosion in a Closed Vessel 107
represent the rate of cooling of air heated to the maximum tem-
perature, because heat is being continually added by the continued
combustion of the mixture. This will be fully proved by a study
of the curves.
It may, however, be taken as completely proved by the
complete accord of all physicists who have experimented on the
subject, that for some reason nearly one-half of the heat present
as inflammable gas in any explosive mixture, true or dilute, is
kept back and prevented from causing the increase of pressure to
be expected from it, Although differences of opinion exist on the
cause, all are agreed on the fact ; they also agree in considering
that inflammation is complete when the highest pressure is
attained.
TEMPERATURES OF EXPLOSION.
With a mass of any perfect gas confined in a closed vessel the
absolute temperatures and pressures are always proportional ; double
temperature means double pressure. Temperatures T, / (absolute),
T T*
pressures corresponding P,/; then - = - (Charles's law). If ex-
t p
plosive mixtures behaved as perfect gases, the pressure before
explosion and temperature being known, the pressure of ex-
plosion at once gives the corresponding temperature. It has
been shown at page 82 that explosive mixtures do not fulfil
this condition, but change in volume from chemical causes
quite apart from physical ones. It follows, therefore, that these
changes must be known before the temperature of the explosion
can be calculated from the pressure. In the cases of hydrogen
and carbonic oxide true explosive mixtures with oxygen, a
contraction of volume is the result of combination. It comes to
the same thing as if a portion of the perfect gas in the closed
vessel was lost during heating ; the temperature then could not
be known at the higher pressure unless the volume lost is also
known.
Suppose one-third of the volume to disappear, upon cooling
to the original temperature, the pressure would be reduced to
two-thirds of the original pressure, and this fraction of the
original pressure must be taken as /t = io. As both steam and
io8 The Gas Engine
carbonic acid at temperatures high enough to make them, per-
fectly gaseous occupy two-thirds of the volume of their free
constituents, it follows that /! must be taken as f /, wherever
the temperatures are such that combination is complete. But
here another difficulty occurs. Bunsen found that hydrogen
and oxygen in true explosive mixtures gave an explosion pressure
of 9 '5 atmospheres. The calculated pressure for complete combus-
tion, and allowing for chemical contraction is 2 1 -3 atmospheres. It
is evident enough that complete combustion has not occurred, but
it is difficult to say what fraction remains uncombined. Yet
unless the fraction in combination be known the contraction cannot
be known, and therefore the temperature corresponding to the
pressure cannot be known.
Berthelot has pointed out that in a case of this kind the true
temperature cannot be calculated, but it may be shown to lie
between two extreme assumptions, both of which are erroneous.
(1) Temperature calculated on assumption of no contraction.
(2) Temperature calculated on assumption of the complete
contraction.
Let the two temperatures be (i) x1 and (2) T.
T1 T
2 vols. H, i vol. O, explosion pressure) 0£ q8oo°r
(absolute) 9-9 atmospheres . . >
2 vols. CO, i vol. O, explosion pressure) 2612° C 4.140° C
(absolute) io'8 atmospheres . . I
The lower temperature could only be true if no combination
whatever had occurred, which is impossible, as then no heat at all
could be evolved; the higher temperature could only be true if com-
plete combination, and therefore complete contraction, occurred.
The truth is somewhere between these numbers.
When the explosive mixture is dilute, the limits of possible
error are narrower, because the possible proportion of contraction
is less ; with hydrogen and air mixture in proportion for complete
combination, 2 volumes of hydrogen require 5 volumes of air.
The greatest possible contraction of the 7 volumes is therefore i
volume. If all the hydrogen burned to steam, the 7 volumes
contract to 6 volumes. With more dilute mixtures the pro-
portion diminishes.
With a mixture containing -J- of its volume hydrogen, 10
Explosion in a Closed Vessel
109
volumes can only suffer contraction to 9 volumes. With \ volume
hydrogen, 14 volumes can contract to 13 volumes.
The limits of maximum temperatures for those mixtures are #s
follows (Clerk) :
i vol. H, 6 vols. air, explosion pressure i
(absolute), 557 Ibs. per sq. in. . . >
1 vol. H, 4 vols. air, explosion pressure )
(absolute), 82 7 Ibs. per sq. in. . . f
2 vols. H, 5 vols. air, explosion pressure )
(absolute), 947 Ibs. per sq. in. . . t
T»
826° C.
1358° C.
1615° C.
T
909° C
1539° C.
1929° C.
The possible error is here much less than with true explosive
mixtures ; coal gas is of such a composition that some of its
constituents expand upon decomposition previous to burning, and
so to some extent balance the contraction produced by the
burning of the others. The possible error is therefore still further
reduced. The composition of Manchester coal gas as determined
by Bunsen and Roscoe is as below. The oxygen required for the
complete combustion of each constituent is also given, and the
volumes of products formed.
ANALYSIS OF MANCHESTER COAL GAS. (Bunsen and Roscoe.}
Amount required
for complete
Products
combustion
vols.
vols. O
vols.
Hydrogen, H . , .
Marsh gas, CH4 .
45-58
34 '9
2279
69-8
45-58, H20
104-7, C02 & H.2O
Carbonic oxide, CO
6-64
3'32
6-64, CO2
Ethylene, C>H4 .
4-08
12'24
16-32, CO.>&HoO
Tetrylene, C4H8 .
2-38
14-28 i9'o4,CO.2&HoO
Sulphuretted hydrogen, H2S
0*29
o'43
0-58, H3O&S(X
Nitrogen, N
2-46
2-46
Carbonic acid, CO2 .
3-67
— 3'67
Total ....
1 00 '00
122 "86 O
198-99, CO2 H2O & SO2
When burned in oxygen 100 volumes of this sample of gas
require 122-86 volumes of oxygen, total mixture 222-86 volumes ;
the products of the combustion measure 198 -99 volumes. Calcula-
ting to percentage, 100 volumes of the mixture will contract to 89^4
no
The Gas Engine
volumes of the products. As 100 volumes ot the mixture will
contain 55-1 volumes of oxygen, it follows that if air be used, four
times that volume of nitrogen will be associated with it, that is,
55 -i x 4 = 220*4. The strongest possible explosive mixture ot
this coal gas with air containing 100 volumes of the true explosive
mixture will be 320*4 volumes, and it will contract upon complete
combustion to 309-8 volumes.
One volume of this gas requires 6*14 volumes air for complete
combustion, and 100 volumes of the mixture contract to 96*6
volumes of products and diluent. A contraction of 3*4 per cent.
Dilution still further diminishes the change ; thus a mixture, i
volume gas 13*28 volumes air, will have only half that contraction,
or 1*7 per cent.
From these figures it is evident that the limits of possible
error in calculating temperature from pressure of explosion does
not exceed, in the worst case, with coal gas and air 3*4 per cent.,
and in weaker mixtures half that number. The fact that the whole
heat is not evolved at the explosion pressure, and that therefore
the whole contraction does not occur then, further reduces the
error. It is then nearly correct to calculate temperature from
pressure without deduction for contraction. This has been done
for Glasgow gas and for the Oldham gas experiments by the
author.
EXPLOSION IN A CLOSED VESSEL. (Clerk.}
Mixtures of air and Glasgow coal gas.
Temp, before explosion . . . . . i8°C.
Pressure before explosion . . . ... atmos. 147 Ibs.
Mixture
Max. press, above atmos.
in pounds per sq. in.
Temp, of explosion
calculated from
observed pressure
Gas.
Air.
vol.
13 vols.
52
1047° C.
vol.
ii vols.
63
1265° C.
.vol.
9 vols.
69
1384° C.
vol.
7 vols.
89
1780° C.
vol.
5 vols.
96
1918 C,
Explosion in a Closed Vessel
1 1 1
Mixtures of air and Oldham coal gas.
Temp, before explosion . ...
17° C.
Mixture
Max. press, above
atmos. in pounds
per sq. in.
Temp, of explosion
calculated from
observed pressure
Theoretical temp,
of explosion if all
heat were evolved
i
Gas. Air.
vol. 14 vols.
40
806° C.
1786° C.
vol. 13 vols.
5!'5
1033° C.
i9i23C.
VOl. 12 VOlS.
60
1202° C.
2058=0.
vol. ii vols.
61
1220° C.
2228° C.
vol. 9 vols.
78
iS57° C.
2670° C.
vol. 7 vols.
87
1733° C.
3334° C.
vol. 6 vols.
90
1792° C.
3808 J C.
vol. 5 vols.
91
1812° C.
vol. 4 vols.
80
1595° C.
Those temperatures calculated from maximum pressure,
although not quite true are very nearly so, whatever be the theory
adopted to explain the great deficit of pressure. It does not follow,
however, that they are the highest temperatures existing at the
moment of explosion ; they are merely averages. The existence of
such an intensely heated mass of gas in a cold cylinder causes
intense currents, so that the portion in close contact with the
cold walls will be colder than that existing at the centre. There
will be a hot nucleus of considerably higher temperature than
that outside, but whatever that temperature may be, the increase
of pressure gives a true average. It may be taken, then, that
coal gas mixtures with air give upon explosion temperatures
ranging from 800° C. to nearly 2000° C., depending on the dilution
of the mixture. The more dilute the mixture the lower the
maximum temperature ; increase of gas increases maximum tempe-
rature at the same time as it increases inflammability.
The author has made explosion experiments in the same
vessel with mixtures previously compressed, and finds that the
pressures produced with any given mixture are proportional to
the pressure before ignition, that is, with a mixture of constant
composition, double the pressure before explosion, keeping tempe-
rature constant at 18° C., doubles the pressure of explosion. The
experiments are laborious, and they are not yet complete for pub-
lication, but the general principles already developed are true for
compressed mixtures also.
1 1 2 The Gas Engine
EFFICIENCY OF GAS IN EXPLOSIVE MIXTURES.
Rankine defines available heat as follows :
' The available heat of combustion of one pound of a given
sort of fuel is that part of the total heat of combustion which is
communicated to the body to heat which the fuel is burned ;
and the efficiency of a given furnace, for a given sort of fuel, is the
proportion which the available heat bears to the total heat.'
The gas engine contains furnace and motor cylinder in one ;
nevertheless the efficiency of the working fluid is quite as distinct
from the furnace efficiency as in the steam engine. Rankine's de-
finition is quite true for the gas engine.
The fuel being gas, the working fluid consists of air and its fuel
and their combinations ; the available heat is that part of the
heat of combustion which serves to raise the temperature of the
working fluid ; the part which flows into it to make up for loss to
the cold cylinder walls cannot be considered available. To be
truly available it must either increase temperature, or keep it
from falling by expansion. The heat flowing through the
cylinder walls is a furnace loss, incident to the explosion method
of heating.
The experiments upon explosion in a closed vessel provide
data for determining the furnace efficiency as distinguished from
that of the working fluid. The proportion of- heat flowing from
an explosion to the walls in unit time will depend upon the
surface of the walls for any given volume. The smaller the
cooling surface in proportion to volume of heated gases, the
slower will be the rate of cooling. Therefore to be applicable to
any engine, the explosion vessel in which the experiments are
made should have the same capacity and surface as the explosion
space of the engine.
The author's experiments are therefore only strictly applicable
to engines with cylinders similar to his explosion vessel. Within
certain limits, however, the error introduced by applying them to
other engines is inconsiderable.
Assuming the stroke of a gas engine (after explosion) to take
0-2 second, this may be taken as the time during which the
pressure of explosion must last if it is to be utilised by the
Explosion in a Closed Vessel 1 1 3
engine. In a closed vessel the pressure falls considerably in 0-2
second, the average pressure may be taken as nearly indicating
the available pressure during that time. The heat necessary to
produce that pressure is the available heat ; and its proportion to
the total heat which the gas present in the mixture can evolve is
the efficiency of the gas in that explosive mixture.
With Oldhamgas the best mixture is (table, p. 103) i volume
gas 1 2 volumes air ; the average pressure during the first fifth of
a second is 51 Ibs. per square inch above atmosphere. If all
the heat present heated the air, the pressure should be 103 Ibs.
effective, so that the efficiency of the heating method is ^^ =
0-49.
The strongest mixture which still contains oxygen in excess
is i volume gas 7 volumes air, the average available pressure is
67 Ibs. per square inch (all heat evolved would give 168 Ibs.), the
efficiency is T6^7¥ = 0*40 nearly.
Calculated in this way the efficiency values for Oldham gas
mixtures are :
Prop, of Oldham gas in mixture . ^, TV TS, TZ, TO* i. y-
Heating efficiency . . . 0*40, 048, o'5o, 0*43, 046, 040, o'37.
The furnace efficiency plainly diminishes with increased
richness of the mixture in gas.
TIME OF EXPLOSION IN CLOSED VESSELS.
The rates of the propagation of flame in explosive mixtures
given in tables, pages 86 and 87, are true only where the
inflamed portion is free to expand without projecting itself into
the unignited portion. They are the rates proper for constant
pressure.
Where the volume is constant, in a closed vessel, the part first
inflamed instantly expands and so projects the flame surface into
the mass, compressing what remains into smaller space.
To the rate of inflammation at constant pressure are added
the projection of the flame into the mass by its expansion
and also the increased rate of propagation in the unignited
portion by the heating due to its compression by portion first
inflamed.
i
H4 The Gas Engine
It follows that the rate continually increases, as the inflamma-
tion proceeds until it fills the vessel.
This is evident from all the explosion curves. The pressure
rises slowly at first, then with ever increasing rate till the explosion
is complete ; thus the explosion curve for hydrogen mixture with
air f - H J, shows an increase of 17 pounds in the first 0*005
second, the maximum pressure of 80 pounds being attained in the
next 0-005 second. With the weaker mixtures the same thing
occurs, rise of pressure, slow at first, then more rapid, and in
some cases becoming slow again before maximum pressure. The
time taken to get maximum pressure varies much with the circum-
stances attending the beginning of the ignition. If a considerable
mass be ignited at once, by a long and powerful spark, or by a
large flame, the ignition of the weakest mixture may be made
almost indefinitely rapid. Something very like Berth clot's explo-
sive wave may result. This is due to the great mechanical
disturbance caused by the rapid expansion of the portion first
ignited ; the smaller that portion is the more gently does the
flame spread. A small separate chamber connected with the
main vessel, if filled with explosive mixture and ignited, will
project a rush of flame into the main vessel and cause almost
instantaneous ignition. The shape of the vessel, too, has a great
effect upon the rate. Where it is cylindrical and large in diameter
proportional to its axial length, ignition is extremely rapid, the
flame is confined at starting, and is rapidly deflected by the
cylinder ends, and so shoots through the whole mass.
By so arranging the explosion space of a gas engine that some
mechanical disturbance is permitted, it is easy to get any required
rate of ignition even with the weakest mixtures.
The maximum pressure is not increased by rapid ignition.
Starting the ignition from a small spark, the time taken to
ignite increases with the volume of the vessel.
Berthelot has experimented upon this point with explosion
vessels of three capacities, 300 cubic centimetres, 1500 cubic
centimetres, and 4000 cubic centimetres. He finds time of
explosion (he also takes maximum pressure to indicate complete
Explosion in a Closed Vessel 115
explosion) of mixture 2 vols. H, i vol. O, and 2 vols. N, in 300
cubic centimetre vessel, 0*0026 second; and in 4000 cubic
centimetre vessel, 0*0068 second.
With mixture of carbonic oxide and oxygen, 2 vols. CO, i vol.
O, smaller vessel, 0-0128 second; larger vessel, 0*0155 second.
Mixtures with air were much slower. The conclusion then is
obvious, that in large engines the time of explosion will be longer
than in small ones.
I 2
n 6 The Gas Engine
CHAPTER VII.
THE GAS ENGINES OF THE DIFFERENT TYPES IN PRACTICE.
HAVING now studied the theoretic efficiency of the different
kinds of engine and the mechanism of the heating method— that
is the properties of gaseous explosions — the way is clear for
the study of the results obtained from the engines in practice.
It is quite evident that no practicable engine can give an
efficiency at all approaching theory from the use of gaseous
explosions ; the temperatures and therefore pressures produced
fall far short of that due to the complete evolution of the heat
present in the mixture as combustible gas. All the heat of
the gas does not go to increase the temperature of the working
fluid ; a large proportion of it is rendered latent in some way
when the maximum temperature is attained.
The appearance of the diagrams from the explosion of mixtures
commonly used in gas engines, shows at first a very rapid increase
of pressure and temperature, which terminates abruptly and is
immediately succeeded by a fall which is relatively a slow one.
It was formerly supposed that the completion of the explosion
was coincident with the completion of the combustion, and there-
fore of the evolution of heat. This, however, was shown by
Bunsen and those who have followed him, to be untrue ; although
the temperature ceases to rise, and fall sets in, the gas present
has in few explosions been more than half-burned at the moment
of maximum temperature. The causes which suppress the heat of
the explosion and prevent it from being evolved at once are com-
plex and have occasioned different explanations which will be fully
discussed in a subsequent chapter. Meantime, it is sufficient
to recognise the fact and to understand its bearing upon the
economy of gas engines.
Gas Engines of Different Types in Practice n?
It is a phenomenon common to all gas engines which have
ever been constructed, whether using compression previous to ig-
nition or not. The heat so suppressed appears when cooling sets in,
and consequently explosive mixtures cool more slowly in appear-
ance than would a mass of air heated to similar temperatures and
exposed to similarly cold enclosing walls.
In many gas engines the indicator diagrams are apparently
almost perfect, that is, the lines of falling temperatures are
almost true adiabatics. So far as the diagram yields informa-
tion, the gases in expanding are losing no heat whatever to the
cylinder, but the temperature is falling apparently only by work done
upon the piston. This supposition is known to be untrue, because
the gases are at a temperature often as high as the hottest of
blast furnaces, and the. walls enclosing are at most at the boiling
point of" water. It is the suppressed heat which is being evolved
during fall of temperature which sustains the temperature and
makes the diagram appear as if no loss or but little was going on.
An actual engine therefore may give a diagram which is the exact
theoretical one, and yet the efficiency of the engine be much
below theory. The author's experiments upon explosive mixtures
were undertaken to get the data necessary for the interpretation of
the diagram, and the rising and falling curves, showing times of
rise and fall of pressure, give the efficiency of coal gas in the
different mixtures, apart altogether from theoretic considerations.
Whatever the opinions held regarding the cause or causes of the
suppression of heat, the experiments with carefully proportioned
explosive mixtures, at known temperatures and pressures, deter-
mme absolutely the capability of gas for producing pressure and
for sustaining it under cooling.
As the efficiency may be very different from that shown by
the indicator, it is advisable to distinguish between the real and
apparent efficiency. Call the one apparent indicated efficiency,
and. the other actual indicated efficiency.
The apparent indicated efficiency, when multiplied by the effi-
ciency of the gas in the particular mixture used, will givethe actual
indicated efficiency. For instance, if the diagram gave the efficiency
of an engine as 0-29 and the efficiency of the mixture was 0-48, then
the actual indicated efficiency is 0-29 xo'48=o-n. That is, only
1 1 8 The Gas Engine
0-48 of the gas present when the diagram is taken really acts
in producing elevation of temperature; the remaining 0-52 is sup-
pressed and keeps up the temperature, which would otherwise fall
by cooling. The diagram alone can never tell accurately the
losses which are taking place unless the heat is all evolved at once
and appears in temperature; then, but not till then, will the lines
traced by the indicator tell the loss of heat. Some previous
writers have misinterpreted their indicator diagrams through
neglect of this fact.
Some others, notably Dr. Slaby, of Berlin, have assumed that
the phenomenon of retarded combustion is produced by invention
and occurs only in the Otto engine. This is a mistake. All engines
using explosion necessarily exhibit it ; in fact, as it is an accom-
paniment of all explosions, it is impossible to make an engine in
which it is avoided.
In the following examination of the performances of the
various engines in practice the importance of the phenomenon will
appear.
Type i. — The most important engines of this type which have
yet been in public use are those of Lenoir, Hugon, and Bisschoff.
Many others have been made and sold in some numbers, but as
these three present fully all the peculiarities of the type, it would
only waste time to describe the varied mechanical details consti-
tuting the sole novel points in the others.
LENOIR ENGINE.
The Lenoir engine as made differs considerably from that
described in his specifications. As a rule of almost general appli-
cation, specifications are untrustworthy as accurate descriptions of
working machines ; the author has been careful to describe no
engine which he has not examined.
Fig. 22 is a section of the cylinder of a half-horse power
Lenoir engine. The engine in the Patent Office Museum, South
Kensington, is well made and in external appearance closely re-
sembles an ordinary high-pressure steam engine.
The cylinder is 5^ inches diameter, and the stroke is 8 \ inches.
Its cylinder is provided with two valves ; both are slides, working
Gas Engines of Different Types in Practice 119
between the cylinder faces and covers, which are held down to the
slides by adjusting screws. One valve controls the discharge
of the products of combustion, the other, the admission and
mixing of the inflammable gas and air. The ignition is effected
by the electric spark. .The working cycle of the engine is as
follows :
When the piston is at the end of its stroke, the gas and air ad-
mission valve is open ; the main port in it opens to the atmosphere,
<— [Jg CAS AMD AIR VALVE
MIXING
PLATE
GAS
FIG. 22. — Lenoir Engine Cylinder (sectional plan).
while a smaller port leads from the main port to the gas supply.
The forward movement of the piston draws into the cylinder the
air and the gas, which mix as they enter the main valve port and the
engine admission port. At about half-stroke the supply of mixed
gases is cut. off, so that the cylinder is completely closed off from
the atmosphere and from the gas supply ; an electric spark now
passed into the explosive mixture from a battery and induction coils
causes explosion and the pressure rapidly rises. The piston is
I2O The Gas Engine
thereby pushed on its stroke during the portion remaining to
be completed ; at the end of the stroke the pressure has fallen
by expansion doing work and by the cooling action of the cylinder
walls, to nearly atmosphere again ; the exhaust valve opens and
during the return stroke the products of combustion are expelled
preparatory to taking in a fresh charge upon the next working stroke.
The same operation is repeated upon the other side of the piston
so that the engine is double-acting of a kind. It cannot be con-
sidered as truly double-acting, like the steam engine, as the driving
pressure is not acting during the whole forward stroke, but only
during that portion of it which is not taken up in sucking in
the explosive charge. The fly wheel, because of this, is much
larger than in a steam engine of corresponding dimensions,
and the power is also much less. The valves are both actuated by
eccentrics upon the crank shaft. Each slide requires a separate
eccentric because the exhaust during the whole stroke and the
admission during only half-stroke could not be managed by the
single to and fro movement. To get the best result it is evident
that the least possible power should be expended in introducing
the charge ; therefore, large inlet air ports are required, all the
larger because an eccentric cannot be made, alone, to give a
sudden cut-off. To prevent throttling as the ports approach
the closing points, the total opening must be considerable. The
eccentric is so set that the port is open slightly before the crank
has crossed the centre, so that it may be well open when the
charge begins to enter. In fact it has some lead like a steam
slide, and for the same purpose. The exhaust valve is set
precisely as in the steam engine, and is of similar construction,
except that it is not enclosed in a case, but it is held against the
cylinder face by a cover and screws. Fig. 22 is a sectional plan
of the cylinder, showing the valves and ports ; fig. 23 is a trans-
verse vertical section of the cylinder, showing the valves and valve
covers with gas, air and exhaust ports. The arrows indicate the
direction of the gas and air flow, while mixing and entering the
cylinder, also the exhaust path. As the air port opens to the
cylinder slightly before the piston has completed its stroke, and
a slight pressure may yet remain in the cylinder, the gas port
does not open till a little later. The gas and air do not open
Gas Engines of Different Types in Practice 121
quite simultaneously, although nearly so ; neither do they close
quite together. There is one gas admission port in the slide
leading into the main port ; in the cover there are two ports
between which the slide port passes, taking gas from either, as
is required, for the end of the cylinder which is receiving the
charge. The main valve port opens on the upper side to the air,
and is covered by a perforated plate and a light metal case
furnished with a throttle valve ; the brass plate perforated is
carried downwards and covers the gas port, so that the gas
entering from the supply pipe is not permitted to flow at once into
Gas and
Air mix at
this point
Gas Inlet
FlG. 23. — Lenoir Engine Cylinder (transverse section).
the main port, but must first pass up through the perforations and
mix with the air which is going down through those adjoining.
The mixing arrangement is somewhat imperfect, and is exceed-
ingly sensitive to change of speed in the engine. The throttle-valve
is intended to increase or diminish the supply of air ; by closing
it slightly, the suction upon the gas port is increased, and so
the proportion of the mixture altered. By opening it, the air has
freer access to the cylinder, the pressure is not reduced so much,
and therefore the gas is diminished. The mixing, however, is too
irregular ; as the gas streams are not projected separately into the
122 The Gas Engine
incoming air stream, the gas flows too much in mass into the air
in mass. The igniting points were invariably placed at the upper
part of the cylinder in the cylinder covers. The cylinder and covers
are water jacketed, the water is kept continuously flowing through,
so that the temperature may not become so high as to injure the
cylinder. This is a most necessary precaution in any gas engine
of even moderate power ; the effect of neglect in a Lenoir engine
is very soon observed in complete cutting up of the cylinder ; it
speedily becomes red-hot if allowed to run without water. In-
deed, even with an adequate water supply, the larger engines gave
great trouble ; although the cylinder could be kept cool the piston
could not. It was proportioned too much on steam engine lines,
and when working at full power the incessant explosions upon both
sides caused so rapid a flow of heat into it that the small surface
exposed to the water jacket by the circumference was insufficient
to carry away the heat absorbed by the whole piston area. The
pistons often became red-hot.
The exhaust slide also had rather hard work, and required
delicate adjustment, as the exhaust gases were very hot, often
800° C. ; the expansion of the slide was therefore considerable,
and in order to be pressure tight when hot, the adjusting screws
had to be kept rather easy when cold. The engine when
starting, therefore, always leaked a little at the exhaust valve.
The same thing happened with the admission slide, but to a lesser
degree.
Notwithstanding the large area of the admission port and the
lead given to the admission valve, the closing motion was too
slow to prevent throttling ; accordingly the pressure fell some-
what below atmosphere, while the valve was cutting off preparatory
to explosion. After cutting off a slight delay occurred between the
passing of the spark and the commencement of the explosion ;
the explosion itself took some time to- complete ; it was by no
means instantaneous ; the diagram produced was consequently
imperfect. In addition to all this, the piston being so hot, heated
the charge while it was entering, and so occasioned further
loss.
The lubricating arrangements also were primitive. The
steam engine requiring but little care in lubricating, the gas
Gas Engines of Different Types in Practice 123
engine was not supposed to require more ; and the ordinary lubri-
cating cock was deemed sufficient. All these sources of loss,
inevitable in a first attempt, made the engine comparatively in-
efficient. Notwithstanding all its defects, the Lenoir engine at the
time of its production was the best the world had yet seen, and in
careful hands it did good work and created a widespread interest.
The engine in South Kensington Museum, under the skilful care of
Mr. S. Ford, worked for many years supplying all the power required
for the repair department of the Patent Office Museum. It runs with
perfect smoothness, nothing whatever in its action would enable
one standing beside it to imagine for a moment that the motive
power was explosive. The popular notion of an explosion is always
associated with the idea of a great noise. This, of course, physicists
have always known to be a fallacy, as no explosion makes noise
unless it has access to the atmosphere. An explosion in a closed
vessel makes no sound unless the vessel bursts. In a gas engine
it is only necessary to see that the explosion is not too rapid, but
that time is allowed for the slack of the connecting rod and crank
connections to take up. The explosions used by Lenoir were
seldom more rapid in rise of pressure than is common with all
steam engines. A i -horse Lenoir engine inspected lately by the
author at Petworth House, Petworth, had been at work for the
past twenty years pumping water for the town and is still at work.
It works with smoothness and is altogether more silent in its action
than most modern gas engines. The author finds that many Lenoir
engines are still at work after twenty years' continuous use, notably
two i -horse power engines at the Brewery of Messrs. Trueman,
Hanbury and Buxton, London, arid one i -horse power at the
establishment of Messrs. Day, Son and Hewitt, Dorset Street,
London, all doing hard work with great regularity.
Diagrams and Gas consumption. — Prof. Tresca of Paris has made
experiments with a ^-horse Lenoir engine, and found that it con-
sumed 95 cb. ft. of Paris gas per indicated horse power per hour. The
diagrams from so small an engine hardly do justice to the method,
and as it is desirable to compare the engine with modern engines
using similar volumes of charge the author has taken a diagram from
a paper by Mr. Slade, published in the Journal of the Franklin
Institute, Philadelphia. The engine had a cylinder of eight inches
124
The Gas Engine
diameter and sixteen stroke. The explosion space corresponds
closely to that of the author's experimental explosion vessel.
The diagram, fig. 24, at once shows the truth of the preceding
discussion of the action of the engine.
AB is the atmospheric line, traced upon the indicator card
by the pencil before opening the indicator cock to communicate
with the interior of the cylinder ; it is the neutral position of the
indicator piston while the pressure on both sides of it is at atmo-
sphere ; any pressure from within the cylinder pushes up the piston
and therefore the indicator pencil. Pressure above atmosphere
is registered by lines above that line, pressure below atmosphere
A
Diagram at 50 revolutions, cylinder 8g inches diameter, i6J inches stroke.
FIG. 24. — Lenoir Engine Diagram.
is registered by lines below that line. The card shows three dis-
tinct tracings, each corresponding to one stroke of the engine :
admission of the charge, explosion, expansion and return expel-
ling the products of the combustion. If the cycle is carried
out in a mechanically perfect manner the admission of the charge
should be accomplished without loss by throttling. This is not so.
From the point a to the point b the valve is open enough to give
free access to the cylinder, and accordingly the pressure within the
cylinder is not appreciably lower than that without ; but here the
valve begins to contract its opening at the very moment that
the piston is moving most rapidly, the pressure falls and is a couple
of pounds per square inch below atmosphere when it closes.
When closed, the spark does not at once take effect, so that the
pressure has become n Ibs. per sq. in. total before the igni-
Gas Engines of Different Types in Practice 125
tion begins to cause a rise. Then the ignition itself takes some
time to be completed, here about ^ second ; the piston has,
therefore, moved through a further one-and-a-half-tenth of its
stroke and the heat given by the explosion is not added at strictly
constant volume, as required by theory. Apart altogether from
loss of heat to the cylinder walls, this diagram is mechanically im-
perfect. The valve arrangements should be such that no loss is
incurred in charging and that the explosion follows so rapidly that
the pressure in the cylinder has no time to fall by expansion,
after closing the admission ; the explosion, indeed, should at once
follow the cut-off. In the best of the three lines the pressure has
2035° C. absolute
1534° C. abs.
FIG. 25. — Lenoir Engine Diagram.
fallen to nearly n Ibs. total, and the maximum pressure of the
explosion is 48 Ibs. per square inch total. The average of the
three lines gives a pressure divided over the whole stroke of only
8'3 Ibs. per square inch, which, assuming the diagram from the
other end of the cylinder to give similar results, gives a total ot
2 indicated horse power at 50 revolutions per minute. This is
an exceedingly poor result for so large an engine. The apparent
indicated efficiency is much below that of a theoretical diagram
using the same expansion. Fig. 25 shows in dotted lines a
diagram which will have the same efficiency as the actual diagram
(best of the three lines). If the temperature of the entering
charge has been raised to 100° C., as stated by Mr. Slade, then
the point c upon the diagram corresponds to that tempera-
ture; the point d will correspond to a temperature of 2035° C.
absolute, as the volume has increased from 0-4 to 0-5 and the
1 26 The Gas Engine
pressure from n Ibs. to 147 Ibs. per square inch total at the point
e. The area of the part of the explosion curve d^/may be taken
as equal to the part of the diagram cfg which is resistance due to
the valve action ; the work done upon the piston by the one part
balances the loss by the other : both portions may therefore be
neglected, the dotted lines representing the apparent diagram
efficiency.
The temperatures for calculating maximum possible efficiency
are as follows — they are also marked upon the diagram
T . 2035° absolute.
T1 - • 1534°
/ . . 623°
*l - 1246°
Calculating E from formula (17) p. 57
_
1-408 (/'-/)
T-/
__ T _ (1534-1246) -r 1-408 (1246 - 623)
2035-623
= 0-175.
The apparent indicated efficiency for the best of the three
lines is 0*175. ^ lt were constantly repeated, the actual indicated
efficiency may be obtained by multiplying by the efficiency of the
gas in the mixture used to get the explosion. The numbers got
from explosion in a closed vessel do not quite represent the con-
ditions of loss in a cylinder with a moving piston. In the first
case the loss ot pressure and temperature is due solely to the
cooling effect of the vessel's walls; in the second the moving
piston reduces pressure and temperature by expansion, and at the
same time increases the surface exposed. The increased surface,
however, will not increase the rate of cooling, as the volume is at
the same time increased in a greater proportion. It has been
already shown that cooling of a heated mass of gas is indepen-
dent of the pressure, and depends on the ratio of surface to
volume.
In the engine the volume of the hot gases becomes doubled by
Gas Engines of Different Types in Practice 1 27
expansion, but the surface exposed does not double; the cylinder
surface increases with the volume, but the piston area and cylinder-
cover area remain the same, so that the proportion of surface to
volume diminishes instead of increasing. The heat lost to the
cylinder and piston and cover in the engine will therefore be no
greater than that lost to the enclosing wall of the experimental
explosion vessel in a similar time. It will indeed be somewhat
less, as in the time taken doing work the temperature will fall by
heat disappearing as work. With the closed vessel the fall is due
solely to cooling, so that the average temperature during the time of
exposure is higher. More work is urgently required by careful
physicists to get accurate data. At present the approximation to
the efficiency of the gas in different mixtures by closed vessel
experiments is the best that can be had; it cannot be greatly in
error. The efficiencies obtained from the indicator diagram and
the author's experiments will be lower than the truth, the more so
the greater the expansion. With engines as at present constructed
the difference is but small.
The mixture required to give a temperature of 2035° C. absolute
is, for Oldham gas, i gas 6 air, and the average pressure during
o'3 sec. from complete explosion is 63 Ibs. per square inch above
atmosphere, nearly. The time taken to expand in the engine
after explosion is 0-3 sec. ; the pressure which should be produced
by the explosion of this mixture, if all the heat of the gas went
to heat the air and products, 192 Ibs. per square inch above atmo-
sphere. That is, the difference between 192 and 63 has gone in
heat suppressed at the moment of complete explosion and heat
lost while exposed to the influence of the vessel walls during the
same period as the effective stroke of the engine.
The efficiency of the gas in the mixture is therefore
^2 = 0-33 nearly,
that is, only one- third is really effective in raising temperature.
The actual indicated efficiency will, therefore, be only one-third
of the apparent. Three times the amount of heat accounted for
by the diagram is required to make the gases used in the explosion
show the temperatures and curve of the diagram.
128 The Gas Engine
Apparent indicated efficiency x efficiency of gas = actual
indicated efficiency :
0-175 x °'33 = °'°58
The actual indicated efficiency of the engine is 0-058 or 5-8
per cent, if this diagram be constantly repeated; but as it is the
best of the three lines it requires correction. Taking the worst of the
three diagrams, fig. 24 shows the temperature as follows : T, 2035°
absolute; T1, 1697° absolute ; /, 797° ; /l, 1243° absolute.
The apparent indicated efficiency is E = 0-126.
The actual indicated efficiency is 0-126 x 0-33 = 0*0495 01
4 '95 Per cent, of the total heat given to the engine.
Tresca calculates the heat transformed into work by the Lenoir
tested by him as 4 per cent.
The mean of the best and worst of these diagrams is
which is higher than the result obtained by this distinguished physi-
cist ; but the difference is sufficiently accounted for by the differ-
ence in the dimensions of the engines. Tresca's was only half-
horse, Slade's was two horse.
The Lenoir engine used mixtures ranging in composition from
i gas and 6 vols. air to i vol. gas and 12 vols. air, depending upon
the amount of work upon the engine ; when there was little work
the governor was arranged to throttle the gas and so diminish the
proportion present. This was a bad plan, as will be explained in the
chapter upon governing. But the effect was to make the engine
use all grades of ignitable mixtures from the strongest to the
weakest. Apart, however, from all intentional arrangements for
governing, these engines tended to govern themselves. An increase
of speed always causes the proportion of gas in the mixture to
diminish, because the resistance of the small gas port to flow
increases more rapidly than the larger air port. It follows that if
the ports are proportioned to pass certain volumes at a low rate of
speed, at a higher rate the proportion is disturbed, the smaller
port giving a greater proportional resistance. The effect is seen
in all the diagrams, the ignitions become later and later as the
mixture diminishes in inflammability, and after attaining a certain
Gas Engines of Different Types in Practice 1 29
dilution, ignition ceases altogether, or becomes too slow to be of
any practical use. In the Lenoir type of engine too slow ignition
is an unmixed evil, as the theory of the engine requires rapid igni-
tion. In it the loss of efficiency due to valve and igniting arrange-
ments is considerable. The electric ignition is very delicate and
troublesome. To overcome the defects of the Lenoir, Hugon
introduced his engine, which in some respects was a considerable
advance.
HUGON ENGINE.
The Hugon engine, like the Lenoir, exploded the charge drawn
into the cylinder by the piston at atmospheric pressure : in it,
however, greater expansion and more dilute mixtures were used.
FIG. 26. FIG. 27.
Hugon Engine Cylinder.
Fig. 26 is a sectional plan showing valves, passages and the
cylinder and piston. Fig. 27 is a transverse vertical section
through the cylinder at the line ab. The admission of the charge
and the expelling of the exhaust are accomplished through the
same passage, so that the cylinder has only two ports, as in the
steam engine : two valves are used, one working outside the other*
The inner valve has five ports, two for admitting the charge, one
for exhausting, and two for carrying the igniting flame. The
ignition by flame was first accomplished in a workable manner by
Hugon, although it had been described in several patents long
before his time.
The ports marked i i in the inner slide A are admission, the
130 The Gas Engine
ports marked 2 2 in the inner slide are igniting, ports ; the port 3
is the exhaust passage, alternately communicating with each end
of the cylinder by the long ports 4 4 to the exhaust port 5, pre-
cisely as in a steam engine. The action of the admission ports
is somewhat novel. The object is to secure a rapid opening and
cut-off, bringing the igniting flame on immediately after closing
the cylinder. The valve is actuated from a cam. When the
piston is at the end of its stroke and is moving forward, the
valve A is moving in the same direction, the port 3 is allowing
the exhaust gases to escape from the other side of the piston, the
port i is open to the cylinder and is communicating through the
port 6 or 6, in the outer slide B, with the air and also with
the gas supply. When the piston has taken in sufficient charge,
the cam moves the slide A suddenly forward, so causing the port i
to close on the outer side but not on the inner ; the igniting
port comes on and the flame burning in it inflames the mixture,
filling the engine port, from whence it spreads into the cylinder
itself. As the inner valve cuts off when moving in the same
direction as it does when opening, it is evident that it must cross
back again, to be in the position required to commence opening
at the correct time. While crossing, unless the communication
with the atmosphere and gas supply is stopped in some other way,
it will open at the wrong time ; to prevent this, the outer valve B
is provided. It is actuated from a pin projecting from the main
valve A ; this pin 7 works in the slot 8, and while the main valve
is moving forward after cutting off, the pin strikes the end of the
slot and carries the outer valve with it, causing it to close the port
in the cover which it commands. A small plate and spring give
friction enough to keep the valve in position till it is moved in
the other direction. When the main valve returns, although its
ports open on the engine ports, the outer ends are blinded by the
outside valve which is not again opened till the main valve has
closed. By this ingenious contrivance, a rapid admission and
cut-off are secured with one cam and the main and auxiliary
slides. The engine from which these details are taken is in South
Kensington Museum and is rated at ^-horse power. The valves
are arranged to cut off at about one-third stroke.
The cylinder is 8^ diameter and 10 in. stroke. The clearance
Gas Engines of Different Types in Practice 131
spaces due to the long ports 4 4, the valve ports open to the
cylinder at the moment of explosion, and the space into which the
piston does not enter, make up in all a proportion of products of
combustion equivalent to nearly thirty per cent, of the entire charge.
The effect of this is to cause a considerable difference between
the nature of the mixture in the port and that in the cylinder
itself, the port mixture being much more inflammable than that
in the cylinder. As a consequence the ignition is more rapid
with weak mixtures than in the Lenoir. The gas is supplied to
the air port in regulated amount by means of a bellows pump
worked from an eccentric on the crank shaft ; it mixes with the air
in passing through the valves and port \ the products of combustion
are therefore completely expelled from the port, and nothing but
pure mixture left to be inflamed by the igniting arrangement.
The gas for the internal igniting flame is supplied also from a
bellows pump under slight pressure. This flame is extinguished
by each explosion, and is relighted when the port opens again to
the air by a constant external flame. The action of the exhaust
port in the main slide is so evident as to require no other
explanation than that afforded by the drawing.
The engine works very smoothly, and is a great improvement
upon Lenoir in certainty of action ; all the trouble with the
battery and coil is very simply avoided. To prevent overheat-
ing of the piston, water is injected by means of a tap ; it is
adjusted so that each suck of the engine drawing in mixture also
takes in enough water to keep the piston at a reasonable tempe-
rature. In this the engine was successful ; it was capable of
harder and more continuous work than the Lenoir, and was in
every way more certain in its action even with a considerable
variation in the composition of the explosive mixture used. The
only parts which gave trouble were the bellows pumps controlling
the gas supply to cylinder and igniting port ; these were made of
rubber, and deteriorating after some use gave trouble by leaking
and occasional bursting. In some of the engines in use they
were replaced by metal pumps and a mixing valve. With these
additions the engine in the Patent Office Museum ran for many
years.
Diagrams and Gas Consumption. — According to Professor
K 2
132
The Gas Engine
Tresca, the gas consumed by a Hugon engine of 2 -horse power
was 85 cubic feet per indicated horse per hour.
Fig. 28 is a diagram taken from
a Ahorse engine by the author.
The engine was indicating 078
horse power, the average pressure
being 3-9 Ibs., and the maximum
25 Ibs. per sq. in. The card shows
considerable delay in explosion after
cut-off, notwithstanding the rapid
movement of the igniting slide.
BISCHOFF ENGINE.
The consumption of the non-
compression type of engine is too
high to permit of its use in any but
the very smallest machines ; accord-
ingly the Lenoir and Hugon engines
have long disappeared from the
market, and the type survives
mainly in the BischofT, which is
specially designed for small powers,
mostly under half-horse. It is an
exceedingly ingenious little engine,
and presents many interesting pe-
culiarities.
Fig. 29 is a side elevation, part
in section ; fig. 30 a section arranged
to explain the valve action. In both
figures the similar parts are marked
with similar letters. There is no at-
tempt to gain economy by attention
to theory ; the aim is to get a small
workable engine with the least possible complication. In this it is
very successful. To avoid the complication of a water-jacket,
the cylinder and piston are so arranged that heating is allowable.
The engine is upright and very peculiar in appearance, the
cylinder has cast on it a number of radiating ribs, which by
Gas Engines of Different Types in Practice 133
contact with the air cause conduction of the heat more rapidly
than would otherwise occur. The temperature, however, becomes
very high, and provision is made to prevent injury to the piston.
It is fitted loosely to the cylinder and has no rings, the connecting
FIG. 29.
Bischoff Engine.
FIG. 30.
rod arrangement is seen in the figure (29) ; it takes the thrust of the
explosion in tension, and almost without side pressure upon the
guide. Any side pressure upon the guide is quite prevented from
reaching the piston, and it consequently is never rubbed against
134 The Gas Engine
the cylinder. The pressure of the explosion is so slight that the
leakage is not serious even without rings. The piston moves up,
taking in the charge, the air through the valve i, fig. 30, which is
simply a piece of sheet rubber backed by a thin iron disc. The
pressure of the air opens, and the explosion closes it ; the valve 2,
fig. 29, similarly made but smaller, admits the gas ; the mixture
does not form till the gases have passed the point 3, fig. 30 ;
therefore the explosion does not spread back to the valves.
When the piston gets to the point 4, it crosses a small aperture 5
covered by a light hanging valve ; a flame burning outside in the
flame chamber is drawn in. The explosion then occurs, and the
pressure at once closes all valves and propels the piston. On the
return stroke, the piston valve 7 opens to the exhaust pipe 8, at the
same time closing the passage to the air admission valves. The
cylinder proper requires no lubrication; the guide requires a
Scale i in. — 24 Ibs. ; 3^" diam. of cylinder ; n^ ins. stroke.
FIG. 31.
Diagram from i-man power Bischoff Engine ; 112 revs, per min. (Clerk.)
little, but the projection of the cover and a draining hole prevent
accumulation and overflow of oil into the cylinder. This pre-
caution is very necessary, because of the high temperature of both
piston and cylinder; without it speedy charring and choking
up of the cylinder would result. The arrangements are crude
and the engine is somewhat noisy, but it is very reliable, and suits
the purpose for which it is designed exceedingly well.
Diagrams and Gas Consumption. — The diagram is very similar
to the Lenoir. Fig. 31 is a diagram taken from a i-man power
engine by the author.
The consumption is, as might be expected, rather higher than
Lenoir. According to tests made at the Stockport Exhibition it
uses 120 cubic feet per actual horse power per hour.
Gas Engines of Different Types in Practice 135
TYPE (!A).
Free Piston Engines. — The very high consumption of gas
common to the engines described prevented their extended use,
and set inventors to work to produce some method which would
give better results. It was very obvious that there was a large
loss of heat ; the trouble with cylinders and pistons made this
abundantly evident. Devices proposed for increasing power by
the injection of water spray, and steam, in various ways failed
to produce good effect except in aiding lubrication. The inventors
of the day seem to have reasoned somewhat in this fashion. The
force generated by an explosion of gas and air is an exceedingly
evanescent one, a high pressure is produced, but it lasts only for
a very short time ; if work is to be obtained before loss by
cooling absorbs all the heat, it must be done rapidly. The
reason why the Lenoir and Hugon engines give so poor a result
is a too slow movement of piston after the explosion. Therefore,
if a method can be devised permitting greater piston velocity,
better economy will be obtained. In this reasoning there was
considerable truth. It has been already proved that the shorter
the time of contact between the charge after explosion and the
enclosing walls, the greater will be the efficiency of the gas in the
mixture. But this only holds within certain limits. If the expan-
sion is too rapid before explosion is complete, then a loss instead
of a gain will occur; the expansion should not commence till
maximum pressure is attained or it will cause a loss of pressure.
Indeed, it is quite conceivable that in engines of the Lenoir type,
the expansion might be so rapid, relatively to the rate of explosion,
that no increase of pressure at all resulted ; in which case no power
whatever would be obtained. The gain then to be expected
arises from rapid expansion after complete explosion. This has
been carried out by several inventors by the free piston method.
Instead of expending the force of the explosion upon a piston
rigidly connected to a crank, the piston is allowed free movement.
The explosion launches it against the atmosphere ; it acquires
considerable velocity, which is expended in compressing the
exterior atmosphere, that is, in producing a vacuum in the cylinder.
When all the energy of motion is expended, the piston comes to
136 The Gas Engine
rest, and the atmospheric pressure forces it back again. So soon
as the return movement commences, a clutch contrivance engages
the shaft and drives it. Engines of type i A may be described as —
Engines using a gaseous explosive mixture at atmospheric
pressure before explosion ; the explosion acting on a piston free to
move without connection with the crank shaft, the velocity being
absorbed by the formation of a vacuum. The power is given to
the shaft on the return stroke under the pressure of the atmo-
sphere.
As has been stated in the historical sketch, the first to propose
this kind of engine were Barsanti and Matteucci, 1857, but the
difficulties were not sufficiently overcome until the invention of
Otto and Langen, 1866.
Otto and Langen Engine. — This engine consists of a tall vertical
cylinder surrounded by a water jacket ; in it works a piston which
carries a rack instead of a piston rod; the mouth of the cylinder is
open to the atmosphere. Across the top of the cylinder is carried
the fly-wheel shaft ; it cannot be called the crank shaft because
there is no crank. On the shaft there is a toothed wheel which
engages the teeth of the rack ; it runs freely on the shaft while the
piston is on its upward stroke, but by an ingenious clutch arrange-
ment it grips the shaft when the piston moves down. The shaft is
therefore free to rotate in one direction and the piston is free to
move up without restraint, but in moving down it gives the impulse.
The shaft is carried on bearings bolted to the top of the cylinder,
which forms a strong and convenient column for carrying the
mechanism required to accomplish the cycle of the engine. At
the lower end of the column is placed a slide valve which performs
the treble duty of admitting, igniting, and discharging. It is driven
from an intermediate shaft, intermittently, as determined by the
governor of the engine. When working at full load, the move-
ment of a small crank actuated from the shaft, lifts the rack and
piston through some inches, taking in the charge through the slide
valve, which then moves further and brings in the igniting flame.
The explosion ensues and shoots up the piston with consider-
able velocity, the pressure rapidly falls by expansion and soon
gets to atmosphere. The piston however has been moving freely
and therefore has done no work ; all the energy of the explosion,
Gas Engines of Different Types in Practice 137
however, has been given to it. The piston has the energy of explosion
in the form of velocity ; it moves on, the pressure beneath it falling
below atmosphere until all its energy of motion is absorbed in
forming the vacuum. When this occurs it ceases its upward flight
and returns, the outer atmosphere driving it back, and as the clutch
has engaged the shaft, an impulse is given. The actual work is
FIG. 32. — Otto and Langen Engine (vertical section).
therefore done by the atmosphere on the down stroke, the explosion
being spent in obtaining energy in a form conveniently applic-
able. If no cooling of the hot gases occurred upon the down
stroke the compression line would return to the point where the
expansion line touched atmosphere ; then the exhaust valve would
open and the gases would be discharged at atmospheric pressure-
138 The Gas Engine
In that case the work done by the atmosphere and weight of piston
on the downward stroke would exactly equal the energy of the ex-
plosion while falling by expansion to atmospheric pressure. But the
cylinder does cool the gases while on the upward and downward
stroke, so that the expansion line does not return upon itself ; the
amount of fall below the expansion line is gain and is added to the
energy of the explosion just as the condenser adds to the efficiency
of the expansion of steam. The exhaust gases are expelled by the
piston and a new stroke is commenced. At full power the piston
makes about 30 strokes per minute, the shaft rotating about 90
revolutions per minute. The governor of the engine is so arranged
that when the speed becomes too great, a lever disengages a pawl
from a ratchet and disconnects the small crank lifting the piston.
The charge is not taken in till the speed falls, and then the pawl
is again allowed to connect the small crank to the main shaft
The ignition slide gets its motion from the small crank shaft, so that
it is arrested or moved along with the piston. The piston
remains at the bottom of the stroke till it is wanted for another
explosion.
Fig. 9, p. 21, shows the general arrangement of the engine, and
fig 32 is a vertical section showing the clutch and section of the slide
valve. Fig. 33 is an elevation, part in section.
A is the cylinder ; B is the piston to which is attached the
rack c ; D the toothed wheel containing the clutch engaging
the rack to the power shaft. The rack is strongly guided. E is
the fly-wheel shaft on which is keyed the fly wheel F and the
driving pulley G ; H water jacket ; i the port for inlet of the
explosive mixture and discharge of the products of combustion ;
K the slide valve serving to admit, to ignite the charge and to dis-
charge the products of combustion ; it is actuated from the small
shaft L by the pin M ; the ratchet N and the pawl o connect the
small shaft to the main shaft when requisite, as determined by the
governor lever p.
This engine is the result of great care and labour on the part
of the inventors; it is greatly superior in economy and efficiency
to any preceding it, and its only fault is its excessive bulk and
weight and the great noise made by it when in action. The whole
of the energy of the explosion being expended in giving the piston
Gas Engines of Different Types in Practice 139
velocity, just as in a cannon, the recoil is considerable. So
serious is it that none but the very smallest engines can be placed
upon upper floors without special strengthening. The author has
seen an engine at work where the vibration produced was so great
that props were put under the engine from floor to floor through
four floors to get a solid resistance in the basement.
FIG. 33. — Otto and Langen Engine (elevation).
In other cases strong iron beams placed diagonally at the angle
of a stone wall carried the engine; notwithstanding these precau-
tions much vibration was caused. These difficulties did not
seriously affect the sale of the engine for small powers, but they
quite prevented it being made for powers above 3-horse. The
clutch also is a matter of great difficulty, the whole power of the
140
The Gas Engine
engine passes through it and it must act freely and instantaneously.
The faintest back lash would allow the accumulation of so much
velocity by the return that even a strong arrangement would be
destroyed. For this reason the pawl and ratchet of Barsanti and
Matteucci failed completely.
Messrs. Otto and Langen's clutch is one of the main points of
their invention and is excellent. It is shown in detail at fig. 34.
The part a is keyed to the shaft; on it runs the part b carrying
Gas Engines of Different Types in Practice 141
the teeth engaging the rack. So long as b moves in the direction
of the arrow i, or is stationary, a revolves freely with the shaft in
the direction 2. The steel slips t, t, c, c are wedge-shaped on the
back, so is the interior of the part b at the positions d, d, d, d.
So long as the rack is stationary or ascending, the steel rollers
e, e, e, e, run freely clear of the inclined surfaces ; immediately the
rack moves down at a rate greater than the movement at A, then
the rollers are firmly wedged between the two inclined surfaces
and the steel slips c, c, c, c grip the part a firmly and drive the
shaft. When the bottom of the stroke is reached the wedges loose
again and the piston is free.
Diagrams and Gas Consumption. — The author has made a set
of experiments upon an engine of 2-horse power working with
Oldham coal gas.
The cylinder is 12-5 inches diameter and the longest stroke
observed was 40-5 inches. Working at the rate of 28 ignitions
per minute, the indicated power was 2*9 horse, and the gas was
consumed at the rate of 24-6 cubic feet per i.h.p. per hour. The
brake power is 2 horse, so that the brake consumption is at the
rate of 36 cubic feet per horse power per hour. This does not
include the consumption of the side lights which is in all 12 cubic
feet per hour.
Fig. 35 is a diagram from the engine when at full power.
The full line is that traced by the indicator, and the dotted
line is the real line of pressures marred by the oscillation of the
indicator pencil.
Professor Tresca, tested a half-horse engine at the Paris Ex-
hibition of 1867; it gave 0-456 brake horse, and consumed gas at
the rate of 44 cubic feet per brake horse power per hour. This es-
timate did not include the side lights. The author's test gives a
better result than that of M. Tresca, but this is due to the fact of
the larger engine being used. It is probable that a 3-horse engine
would give a consumption of about 30 cubic feet per brake horse
power per hour.
The interest excited by the engine at the time of its first trial
was naturally great, and many explanations were advanced of the
cause of its superiority over the Lenoir and Hugon engines.
Strangely enough the theory of the engine has been at best but
I42
The Gas Engine
imperfectly stated by previous writers; some indeed have fallen
into grave error respecting its action. It is therefore essential
that it should be somewhat fully considered here.
The name by which it is most widely known is in itself mis-
leading. Atmospheric gas engine at once suggests the Newcomen
steam engine and further suggests the substitution of flame for
Gas Engines of Different Types in Practice 143
steam, vacuum in both cases being supposed to be produced by
condensation. In the steam engine the name truly describes the
action : the piston is drawn up, the cylinder filled with steam at
atmospheric pressure and the steam condensed by a water jet ;
then the atmosphere presses the piston down and gives the power.
In the gas engine cooling has little to do with the production
of the vacuum ; the vacuum would be produced and the engine
would act efficiently without any cooling action of the cylinder
whatever. The diagram fig. 35 proves this very clearly. While
the piston is moving from the point a to b by the energy stored
up in the fly wheel, the charge enters the cylinder; at b the piston
pauses, and, the igniting flame being introduced, the charge ex-
plodes, the pressure rises to 54 Ibs. per square inch above atmo-
sphere. The appearance of the explosion curve does not indicate
truly the rate of increase, because the piston is completely at rest
till the pressure puts it in motion. The piston moves up impelled
by the pressure of the explosion; as it moves the gases beneath it
expand and therefore the pressure falls. At the point d the pres-
sure is again level with that of the outside atmosphere; here the
explosion ceases to impel the piston and, the pressure in the cy-
linder falling, the atmosphere presents a continually increasing
resistance. But while the piston is passing from the point b to d,
the pressure has been falling from 54 Ibs. above atmosphere to
atmosphere ; the average pressure upon it through this distance is
12-6 Ibs. per square inch; as the distance is 1-3 feet and the piston
area is 1227 inches, 2010 ft. pounds have been expended upon it.
What becomes of this work ? In an ordinary engine it would be
communicated to the crank, and if no load were on, the crank
would give it to the fly wheel. Here there is no crank and the
piston is perfectly free, the piston alone contains the energy ; its
weight has been raised through i -3 feet and the balance of the
energy is stored in it as velocity of upward movement.
It must therefore continue to move up till its energy of motion
is expended in compressing the atmosphere, in raising the piston,
and in friction. If friction did not exist and the piston was indefi-
nitely light, then the portion of the diagram bed would be equal
in area to the portion def, that is, the work expended by the ex-
plosion in giving the piston velocity would be equal to the work
144 The Gas Engine
expended by the atmosphere in bringing it to rest again. Once
at rest the vacuum produced allows the piston to be driven down
again, this time to give up its energy to the motor shaft.
As the piston in this engine weighs 116 Ibs. the work spent in
raising it through 1*3 ft. is 116 x i'3= 150*8 ft. pounds; deduct
this from the total work; and 2010 — 151 = 1859 ft. Ibs. is the
energy of motion of the piston.
The relation between energy, mass and velocity is
E = M^.
2
E = energy in absolute units. One foot pound =32 absolute
units.
M = mass in pounds.
v — velocity in feet per second.
The velocity is therefore v = + / £?
V M
and
£=1859x32 = 59488 absolute units.
M = 116
The velocity of the piston at the moment when the explosion
pressure has been expended and the internal and external pressures
exactly balance is 32 ft. per second or 1560 ft. per minute; at no
point of the stroke in any, ordinary engine, steam or gas, is such a
high piston speed possible. This explains the recoil of the engine.
But this is not the average. The piston has attained 32 feet per
second after moving through i -3 feet ; the time taken to move that
distance is / = A/- when / = time in seconds.
V v
s = space passed through.
v = velocity.
and s = 1-3 feet v = 32 feet.
/ = A = 0.2g second.
V 32
The piston has taken o'28 second to move through the 1*3
feet ; its average velocity during the action of the explosion is
Gas Engines of Different Types in Practice 145
therefore 4*64 feet per second or 278 feet per minute. This,
although high, is not greatly in excess of that used in the Lenoir
and Hugon engines. It is less, indeed, than the average piston
speed now used in modern compression engines, 300 to 400 feet
per minute being common. If no cooling by the cylinder occurred,
the line c df would be adiabatic, and the return line fg would
coincide with the expansion line df: the portion of the vacuum
diagram def is due solely to the energy of the explosion, the part
dfg is due to the cooling of the gases. If cooling did not act at
all, the area bed would be greater, and therefore def, which is its
equivalent, would also be greater, that is, the vacuum produced
would be greater if no cooling whatever existed.
The theory of its action generally held at the time of M. Tresca's
experiments seems to have been as follows :
The work of the explosion consists simply in pushing up the
piston and filling the space behind it with flame, which flame is
cooled by contact with the cylinder, and a vacuum results. The
flame is considered as analogous to steam, and the cooling as
similar to condensation as in the Newcomen engine. The inven-
tors of the engine seem to share this erroneous idea ; certainly
M. Tresca did, as in his report upon the engine he says : * There
is, therefore, between the older machines and the new one this
difference of principle, that the pressure in the cylinder can never
descend below the atmospheric during the upward stroke. The
negative force of the atmospheric pressure, useless as it was, be-
comes utilisable. . . .' He clearly considered that the pressure
during the upward stroke was expended only in lifting the pistcn
through a certain height, and as soon as it fell to atmosphere the
piston stopped and the cooling caused a vacuum, the work being done
by the falling of the piston and the pressure of the exterior air.
If the cooling really caused the vacuum, the diagram would be
quite different ; instead of the pressure touching atmosphere at the
point d, it would not touch till the point e at the end of the stroke.
The pressure would then abruptly fall to / and the piston would
return. M. Tresca observed that the pressure did fall below
atmosphere before the end of the stroke, but he considered it as a
defect. ' In reality the piston rises in virtue of the swiftness ac-
quired to beyond the position at which there would be equilibrium
146 TJie Gas Engine
between the interior and exterior pressure. But that one small
loss of power is amply compensated for by the atmospheric power
of the downward stroke.'
The very principle of the engine really depends upon this fall
of pressure which was considered by M. Tresca a defect ; it is the
only way to store up the power of the explosion so that it may be
available on the downward stroke. If the pressure did not fall,
the piston would require to be projected 10-5 feet into the air to
absorb the energy of the explosion in its mass alone ; by the fall
of pressure it is absorbed with the smaller movement of i'8 feet.
The only part of the diagram due to cooling is the part dfg, not
more than one- fifth of the total area representing work done by
the engine.
The superior economy, it is evident, cannot be altogether due to
greater piston velocity ; the piston velocity, although considerable,
is not superior enough to that of Lenoir and Hugon to account
for all the difference. There must exist other points of dissimi-
larity. In the Lenoir type of engine the strokes were numerous
and the gas consumed per stroke on the whole smaller than in
Otto and Langen engines of equal power : the latter used few
strokes but large cylinders ; proportionally the cooling surface
exposed was thus diminished. Then the piston is at rest until
the explosion puts it in motion ; the pressure gets time to rise to
its maximum before the piston moves and expands the space.
Maximum pressure is attained at constant volume as required by
theory ; at the same time the piston and cylinder remain cool be-
cause of the infrequency of the strokes. The entering charge is
therefore but slightly heated before explosion, and the explosion
gives a better pressure for a smaller elevation of temperature.
The most potent cause of improvement, however, is great ex-
pansion : the large cylinders allow an expansion of 10 times the
volume existing before explosion, and so gain, first by expanding
to atmosphere, and second by the cooling which follows the further
expansion. A comparison of the actual diagram with the theo-
retical reveals some interesting peculiarities which seem hitherto
to have escaped observation. The maximum pressure on the
diagram, which is above the true pressure, fig. 35, is 54 Ibs. above
atmosphere, corresponding to a temperature of 1355° absolute.
Gas Engines of Different Types in Practice 147
The mixture exploded contains i volume gas and 7 volumes air
^Oldham gas) ; if all the heat present had been evolved by the
explosion the pressure should have been 168 Ibs. above atmo-
sphere. At the maximum pressure only 32 per cent, of the heat has
been evolved, leaving 68 per cent, to be evolved during the ex-
pansion. The line c d is very much above the adiabatic, so much
so that the curve c d is nearly isothermal, the temperature at d only
becoming 1305° absolute instead of 733°, which it should be if adia-
batic. The heated gases are therefore gaining heat from c to d, and
as the only source is combustion, it follows that the combination
is not nearly complete at the maximum pressure. The 68 per cent.
Scale i in. = 24 Ibs. Diluted mixture, gas i vol., air 12 vols.
FIG. 36. — Diagram from 2 h. p. Otto and Langen Engine (Clerk).
•of the total heat which has not appeared at the maximum pressure
is appearing during the expansion. The combustion seems to be
nearly complete at the point d as the line de behaves as if cooling ;
if adiabatic, the temperature at/ should be 961° — it is 870°. During
compression to atmosphere again, the temperature remains con-
stant at 870° ; the cooling power of the cylinder is equal only to
preventing increase which would otherwise occur.
This effect is more evident with a more dilute mixture. Fig. 36
is a diagram taken by the author from the same engine, but using
L 2
148
The Gas Engine
a mixture containing i volume of gas and 1 2 vommes of air. Here
the maximum pressure is only 17 Ibs. per square inch above atmo-
sphere. With complete evolution of heat it should be 103 Ibs. ; the
maximum pressure in this case only accounts for 24 per cent, of the
heat known to be present, leaving 76 percent, to be evolved during
expansion. The diagram affords the most ample proof that the
go
' "So
60
60-
50-
30-
401*1? Absolute
50-
o 10 20 30 40 50 60 70 80 90 100
Percentage of stroke.
FIG. 37. — Otto and Langen Engine. Free Piston.
combustion is proceeding, the falling line shows a steady increase
of temperature to the very end of the stroke. The temperatures,
are marked upon the diagram at the successive points ; taking the
temperature at the point b as 290° absolute, the points c, d, e,f,g, h
are respectively 780°, 936°, 1092°, 1107°, 1160°, and 1225°, show-
ing a steady increase throughout the whole expansion line, right
Gas Engines oj Different Types in Practice 149
to the end of the stroke. The consumption of gas per indicated
HP rises very much in consequence, amounting to about 37 cubic
feet per I HP hour. The power at the same time falls, so that
the 30 explosions per minute are required to keep the engine going
without load at 53 revolutions per minute. The cooling during
compression is so slow that the temperature falls only from 1225°
to 967°, from the point h to k. All the published diagrams examined
by the author show this peculiar effect. Fig. 37 is a diagram pub-
lished by Mr. F. W. Crossley. Taking 80 Ibs. as the maximum pres-
sure, which seems somewhat higher than is warranted by the dia-
gram, the oscillation of the indicator has been so excessive, the cor-
responding temperature is 1873° absolute : the expansion line c d if
adiabatic would give at the point d a temperature of 1090°, the
actual temperature is 1044°. Within the limits of error they may
be considered the same ; there is therefore combustion going on
from c to d also. At the point e the temperature is 788° ; if adia-
batic it should be 667°. It is quite evident that the whole of this
expansion curve is above the adiabatic ; in the earlier part of the
diagram the oscillation causes uncertainty, but in the latter part
the measurement is true enough.
The compression line ^is almost isothermal, 788° at e, cooling
to 737° at#
Fig. 38 is a diagram by Releaux taken from Schottler.
It is manifestly wrong, as the vacuum part is much too small
and the maximum temperature is higher than has ever been ob-
tained by any explosion of gas and air, but if taken as relatively
correct the expansion line is much above the adiabatic.
From his study upon the explosion of gas and air mixtures in
•closed vessels, the reader will be prepared to find that only a
portion of the total heat present is evolved by explosion in any
gas engine. That is, the explosion maximum pressure never accounts
for the whole heat present as inflammable gas ; a portion is in some
manner suppressed and is not evolved till long after the moment
of complete explosion. Combustion is not completed till con-
siderably after the completion of explosion.
He will be unprepared, however, for such diagrams as figs. 35
and 36, where the maximum pressure represents only 0*32 and 0*24
of the heat present, and o'68 and 076 are evolved during the forward
ISO
The Gas Engine
stroke while the pressure is falling. The explanation is simple.
The case is quite different from that of the closed vessel or where
the piston is connected to a crank. As soon as the pressure of
the explosion becomes great enough, the piston at once moves out
and prevents further increase of pressure. The slower the rate at
which the mixture inflames, the greater will be the apparent sup-
pression of heat ; thus the mixture i volume gas 7 air takes, in the
closed vessel, 0-06 second to complete the explosion, but before this
FIG. 38. — Otto and Langen.
time has elapsed the piston is in rapid motion reducing the pressure
before complete explosion. To get the maximum pressure it
would be necessary to prevent it from moving till the explosion
was complete. The weaker mixture takes 0-25 second to complete
the explosion, and so in diagram, fig. 36, the temperature actually
rises throughout the whole stroke.
A heavier piston would be longer in starting under the pressure
of the explosion and would so allow a high pressure to be attained
Gas Engines of Different Types in Practice 151
with a given mixture. This explains Mr. Crossley's remark in reading
his paper, that heavy pistons gave a more economical result than
light ones.
Gilles Engine. — The great
success of the Otto and Lan-
gen engine occasioned many
attempts to improve upon
it. Its merits and its faults
were equally evident. The
recoil of the engine at every
stroke was exceedingly trouble-
some, and the noise of the rack
and clutch could be heard at
a long distance. Gilles of Co-
logne invented an engine in-
tended to retain the economy
while reducing the noise. In
it there are two pistons, one
free, the other connected to the
crank in the usual way. The
free piston being at the bottom
of its stroke and close to the
crank piston, the latter moves
a portion of its stroke, taking
in the explosive charge ; at a
suitable position ignition oc-
curs and the free piston is
driven in one direction while
the other completes its out-
stroke. A vacuum is pro-
duced between the pistons,
and the free piston rod being
gripped by a clutch is kept in
its extreme position till the
main piston returns under the
pressure of the atmosphere. FIG. 39.-Gilles Engine. Free Piston.
The clutch is then released and
the free piston falls, expelling the exhaust gases. Fig. 39 is a
152 The Gas Engine
section of the engine. It is unnecessary to give further descrip-
tion, as the engine was not so economical or so simple as the
earlier one.
TYPE II.
In engines of this kind compression is used previous to
ignition, but the ignition is so arranged that the pressure in the
motor cylinder does not become greater than that in the
compressing pump. The power is generated by increasing
volume at a constant pressure. Engines of Type II. are there-
fore :
Engines using a mixture of inflammable gas and air compressed
before ignition and ignited in such a manner that the pressure
does not increase, the power being generated by increasing
volume.
These engines are truly slow combustion engines ; in them there
is no explosion.
The most successful engine of the kind is an American invention;
although proposed in 1860 by the late Sir William Siemens, it was
never put into practicable workable shape till 1873, when the
American, Brayton of Philadelphia, produced his well-known
machine.
Messrs. Simon of Nottingham introduced it into this country in
1878. They added one thing only of doubtful utility — that is, the
use of steam raised in the water jacket as auxiliary to the flame in
the motor cylinder.
Brayton Engine. — In this engine there are two cylinders, com-
pressing pump and motor. The charge of gas and air is drawn
into the pump on the out-stroke and compressed on the return
into a receiver ; the pressure usual in the receiver varies from 60
to 80 Ibs. per square inch above atmosphere. The motor cylinder
takes its supply from the receiver but the mixture is ignited as it
enters, a grating arrangement preventing the flame from passing
back; the mixture, in fact, does not enter the motor cylinder at all ;
what enters it, is a continuous flame. At a certain point the supply
of flame is cut off and the piston, moving on to the end of its stroke,
expands the volume of hot gases to nearly atmospheric pressure
before discharge.
Gas Engines of Different Types in Practice 153
Fig. 40 is an external view of the engine. Figs. 41 and 42 are
sections of the motor and pump cylinders. The action is as fol-
lows : — The engine is single acting, receiving one impulse for every
revolution ; like all gas engines it depends upon the energy stored
up in the fly wheel to carry it through those parts of its cycle
FIG. 40. — Brayton Petroleum Engine.
where the work is negative. The two cylinders are inverted and
are attached to a beam rocking beneath them, by connecting rods.
The beam is prolonged and connected to the crank above it by a
rod ; both cylinders are single-acting and the pistons are of the
trunk kind. Both pump and motor cylinders are of the same
1 54 The Gas Engine
diameter, but the pump is only half the stroke of the motor. The
valves are actuated from a shaft running at the same rate as the
main shaft and driven from it by bevel wheels. There are four
calves, all of the conical seated kind — two upon the motor,,
admission and discharge, two upon the pump cylinder, admission
and discharge. The admission and discharge valves upon the
motor are actuated from the auxiliary shaft by levers and cams, so
is the pump inlet. The pump discharge valve is automatic, rising
at the proper time by the pressure of compression. During the
down-stroke the pump takes in the charge of gas and air, forcing
it on the up-stroke into the receiver. From the receiver it is led to
the power cylinder, passing by the inlet valve through a pair of
perforated brass plates with wire gauze placed between them.
Through this diaphragm a small stream of mixture is constantly
passing into the motor cylinder; before the engine is started, a
plug is withdrawn and the current lighted ; a constant flame is
therefore burning under the diaphragm. The mixture enters the
cylinder through this flame, lighting as it enters ; at all times
during the exhaust part of the stroke, as well as the admission, the
stream of entering mixture, from the receiver, keeps up a small
constant flame which is augmented at the beginning of the stroke,
so as to fill the cylinder entirely, when the admission valve is
opened. When the admission valve is closed, the bye-pass keeps
the flame fed with sufficient mixture to keep it alight. The
pressure in the cylinder thus never exceeds that in the reservoir
and the mixture burns quietly without spreading back.
Figs. 40, 41 and 42. — A is the motor cylinder ; B the pump ;,
the beam and connections require no lettering ; c is the pump
inlet valve (the pump discharge, which is an ordinary lift valve, is
not seen in fig. 42, but is lettered D in fig. 40) ; E the motor inlet ;
F the igniting plug which is withdrawn when the flame is to be lit
before starting the engine (see fig. 82) ; G is the grating in section
(see fig. 41); H the exhaust valve; the levers and cams are
sufficiently indicated on the drawing ; the small pipe and stop-
cock i (fig. 40) communicates at all times with the reservoir and
supplies the constant flame with mixture. The engine worked
well and smoothly ; the action of the flame in the cylinder could
not be distinguished from that of steam, it was as much within
Gas Engines of Different Types in Practice 1 5 5.
control and produced diagrams quite similar to steam. The flame
grating was the weak point ; it stood exceedingly well for a time, but
if by any accident the gauze was pierced in cleaning, the flame
went back into the reservoir and exploded all the mixture — the
engine, of course, pulled up as the constant flame having no supply
1 U.
FIG. 41.— Brayton Engine.
Section of Motor Cylinder.
FIG. 42. — Brayton Engine..
Section of Pump Cylinder^
was extinguished. This accident became so troublesome that
Mr. Brayton discontinued the use of gas and converted his engine
into a petroleum engine. The light petroleum was pumped upon
the grating into a groove, filled with felt, the compressing pump
I S6
The. Gas Engine
then charged the reservoir with air alone. The air in passing
through the grating carried with it the petroleum, partly in vapour,
part in spray; the constant flame was fed by a small stream of air.
The arrangements were, in fact, precisely similar to the gas engine,
except in the addition of the small pump and the slight alteration
in the valve arrangements. The difficulty of explosion into the
reservoir was thus overcome, but a new difficulty arose — the
cylinder accumulates soot with great rapidity and the piston
requires far too frequent removal for
cleaning. The petroleum pump is an
exceedingly clever little contrivance ;
fig. 43 shows its details. The amount
of petroleum to be injected at each
stroke is so small that an ordinary force
pump with clack valves would be un-
certain. Brayton gets over this difficulty
by substituting a slide valve driven from
the eccentric.
The plunger of the pump is no larger
than a black-lead pencil, yet it dis-
charges any quantity, from a single drop
per stroke up to full throw, with un-
erring certainty. The plunger also is
driven from an eccentric. Both eccen-
trics are in one piece and rbtate on the
end of the auxiliary shaft, driven by a
pawl when the engine is in motion ; to
allow of starting, the pump can be
moved by a hand-crank independently.
To start, the air reservoir is filled, if not
already full, by turning the engine round
by hand ; the plug F is then withdrawn
and a little petroleum thrown upon the diaphragm by a few turns
of the pump. The cock i on the small pipe is then opened and
a stream of air flowing from the reservoir vaporises the petroleum ;
it is lit at o, and the flame having enough air for combustion retreats
to the grating and remains burning within the cylinder. The plug
is then inserted, the starting cock opened, and the engine starts.
FIG. 43.
Brayton Petroleum Pump.
Gas Engines of Different Types in Practice 157
The flame remains alight during the whole time the petroleum
continues to be supplied.
The valves act well and the motor cylinder does not suffer
from the action of the flame so long as it is kept reasonably
clean. If the soot, however, is allowed to accumulate, it speedily
cuts up.
Diagrams and Gas or Petroleum Consumption. — Prof. Thurston
of the Stevens Institute of Technology tested a Brayton gas engine
in New York in the year 1873.
The following extracts are from his report :
' The operation of the engine is precisely similar in the action
of the engine proper and in the distribution of pressure in its
cylinder, to that of the steam engine. The action of the impelling
fluid is not explosive as it is in every other form of gas engine of
which I have knowledge.
' Upon the opening of the induction valve, the mixed gases
enter, steadily burning as they flow into the cylinder, and the
pressure from the commencement of the stroke to the point of cut
off, as is shown by the indicator diagrams, is as uniform as that
observed in any steam engine cylinder. The maximum pressure
exerted during my experimental trial, and while the engine was
driving somewhat more than its full rated power, was about 75 Ibs.
per square inch at the beginning of the stroke, gradually dimin-
ishing to 66 Ibs. per square inch at the point of cut-off, where
the speed of the piston was nearly at a maximum, and then de-
clining in accordance with the law governing the expansion of
gases.
' Complete combustion is insured by thorough mixture. This
is accomplished by taking the illuminating gas and air, in proper
proportion, into the compressing pump together, and the mixture
here made becomes more intimate in the reservoir, and in its pro-
gress towards the point at which it does its work. The constantly
burning jet already described insures prompt ignition on entering
the cylinder.
'. . . the engine rated at 5 HP developed, as a maximum,
rather more than its rated power. Its mean power during the test,
as determined by the dynamometer, was 3*986 HP, the indicator
showing at that time 8^2 HP developed in the cylinder. The
Tlie Gas Enine
amount of gas consumed averaged 32*06 cubic feet per indicated
HP per hour.
'The excess of indicated over dynamometric HP is to be
attributed to the work of driving the compressing pump and to the
friction of the machine.
'The greater portion of this appears both in debit and credit
side of the account, since, although expended in the compressing
pump, it is restored again in the driving cylinder.'
The consumption of 32-06 cubic feet per horse hour is incor-
rect ; it is obviously unfair to include the pump diagram in the
gross power. The author has tested an engine of similar con-
struction and dimensions ; he finds the friction of the mechanism
Max. press. 68 Ibs. per ?q. in.
FIG. 44.
FIG. 45. - Diagrams from Brayton's Gas Engine.
to be about i -horse ; adding this number to the dynamometric
power of Prof. Thurston, the legitimate indicated power may be
taken as 5 HP, the consumption is therefore 62 *32'0- =55-2;
5'o
and the gas per brake HP per hour is _'_2— ^^JiL =69-3. These
3-986
numbers, although showing improvement upon the Lenoir and
Hugon, prove that the engine was much inferior in economy to
the Otto and Langen engines,
Mr. H. McMutrie, Consulting Engineer at Boston, took dia-
grams from an engine of similar dimensions which confirm these
results. Fig. 44 is the diagram taken with full load, fig. 45 the
diagram from the motor with no load on, the power being just
sufficient to overcome friction and pump losses.
Gas Engines of Different Types in Practice 159
FULL LOAD DIAGRAM.
Area of piston 50*26 sq. ins.
Speed of piston . , . . . . . 180 ft. per min.
Mean pressure . / 33 Ibs. per sq. in.
Pressure in reservoir 75 '4 Ibs. per sq. in.
Initial pressure in cylinder . . . . .68 Ibs. per sq. in.
Gross power developed . . • , . . . 9 H P.
No LOAD DIAGRAM.
Speed of piston . . . . , . . . 180 ft. per min.
Mean pressure ., . . « . 18 Ibs. per sq. in.
Friction and other resistance . . . . 4^87 HP.
Net available power . . . . 9 — 4-87 = 4-13
This power agrees closely with the actual determination by
dynamometer.
The author has made a careful trial of a Brayton petroleum
engine rated at 5 -horse. The engine was made by the ' New York
and New Jersey Ready Motor Company ; ' it was sent to Glasgow
and the following test was made at the Crown Ironworks on the
2ist and 22nd February, 1878. The motor cylinder is 8 inches
in diameter and the stroke 12 inches ; the pump cylinder is also
' 8 inches diameter but the stroke is 6 inches.
Diagrams were taken from both pump and motor by a well-
made Richards' indicator. At the same time the dynamometer
was applied to the fly wheel fully loading the engine, readings were
taken at regular intervals. The revolutions were recorded by a
counter. The petroleum used was measured in a graduated glass
vessel .
The results are as follows :
TEST OF BRAYTON PETROLEUM ENGINE. (Clerk.}
Petroleum consumed during one hour . . . i '378 gallons.
Mean speed of engine 201 revs, per min.
Mean dynamometer reading . . . -. . 4-26 HP.
Mean pressure, power cylinder . . . . .31 Ibs. per sq. in.
Mean pressure, air pump . .- .. . . 27*6 Ibs. per sq. in.
Piston speed, motor ...... 201 ft. per min.
Piston speed, pump . . . / . . ioo'5 ft. per min.
Power indicated in motor . . . . . 9*49 HP.
Power indicated in pump . . . • . " .' 4'io HP.
Available indicated power . . . ... • 5'39
i6o
The Gas Engine
The power by the dynamometer is 4'26-horse ; therefore the
mechanical friction of the engine is 5-39 — 4-26=1-13 horse.
Consumption of petroleum
Consumption of petroleum
0-255 galls, per IHP per hr.
0-323 galls, per actual HP per hr.
Figs. 46 and 47 are diagrams from the motor and pump, which
are fair samples of those taken. It will be observed that consider-
able throttling occurs in entering the motor cylinder ; the pump
pressure is higher than the reservoir pressure, and the motor pres-
sure is lower, so that a double loss has been incurred. The prin-
ciple of the engine is so good that the author anticipated better
results. Great improvement could be obtained by reproportioning
f/0
Mean pressure 30*2 Ibs. per sq. in. 8 ins. dia. cylinder. Stroke 12 ins. 200 revs, per min,
FIG. 46. — Brayton Petroleum Engine. Motor Cylinder.
60
Mean pressure 27-6 Ibs. per sq, in. 8 ins. dia. cylinder. Stroke 6 ins. 200 revs, per min.
FIG. 47. — Brayton Petroleum Engine. Pump Cylinder.
the valves and air passages ; they are in this engine much too small
and cause needless resistance and loss. The maximum pressure
in the motor cylinder is 48 Ibs. per square inch, which remains
steadily till the inlet valve shuts at four-tenths of the stroke : the
pressure then slowly falls as the gases expand, the exhaust valve
opening at about ten pounds per square inch above atmosphere.
The average available pressure upon this diagram is 30-2 Ibs.
Gas Engines of Different Types in Practice 161
per square inch. The air pump shows a maximum pressure of
65 Ibs. per square inch, the reservoir pressure being 60 Ibs. The
average resistance is 27-6 Ibs. per square inch ; as the pump is half
the stroke of the motor and equal to it in area, the pressure to be
deducted is ^— = 13-8 and 30-2 — 13-8 = 16-4. The actual
available pressure actuating the engine is therefore only 16*4 Ibs.
per square inch. The effect of the clearance in the pump cylinder
is noticeable upon the diagram ; the air inlet valve does not open
till one-tenth of the down stroke is completed.
The theoretic efficiency of this type, with a maximum tempera-
ture of 1600° G, compression of 60 Ibs. per square inch above
atmosphere, and motor cylinder of twice the pump volume, is 0-30 ;
the efficiency of the gas in the mixture commonly used, i volume gas
7 volumes of air, is 0^40 (p. 113) ; so that if the conditions of loss
by cooling are no worse than in the author's explosion experiments,
and the diagram appeared perfect, the actual indicated efficiency
would be o-3o x 0-40 = o'i2. That is, the engine should convert
1 2 per cent, of the heat it gets as gas or petroleum into indicated
work. But the diagram is imperfect in many ways. Using the mix-
ture it does, the diagram should show a maximum temperature of
1600° C. at least ; in reality the highest temperature is only 840° C.
The flame is entering the cylinder at an actual temperature of
1600° C. during the whole period of admission, but the convec-
tion has so greatly increased by the mixing effect of the entering
current that greatly increased cooling results ; accordingly, when the
gases are fully admitted and the inlet valve is closed, the gases have
only a temperature of 840° C. instead of 1600° C. After admis-
sion ceases, the expansion line from 45 Ibs. to 10 Ibs. pressure is far
above the adiabatic, indeed it is isothermal, the combustion is
proceeding and the small igniting flame also is helping to sustain
the temperature.
It is therefore quite evident that the loss of heat is much greater
than that occurring during explosion in equal time. The correction
of the theoretic efficiency indicated by the author's closed vessel
experiments is insufficient, 0-12 is much above the actual effici-
ency. Taking the heating value of the American coal gas used
in Prof. Thurston's experiments as 10,900 heat units per unit weight
M
1 62 The Gas Engine
of gas burned, and one pound of it as measuring 30 cubic feet,
then as the engine used 55 cubic feet per IHP per hour, its
efficiency is 0*071; that is, it converts 7*1 per cent, of the heat given
to it into work.
This is a poor result for a cycle having so high a theoretic
efficiency, and in the author's experiments with petroleum it is
even worse.
The sp. gravity of the petroleum was o '8 5, therefore the weight
of one gallon is 8*5 Ibs. As 0*255 gallons are burned per indi-
cated horse power per hour, this amounts to8'5xo'255 = 2'i6 Ibs.
of liquid fuel per IHP per hour. One pound gives out 11,000
heat units, and for one horse power for one hour 1424 units are
required ; the actual indicated efficiency is therefore
1424 - = -I4M- = 0-06 nearly ; that is, 6 per cent, of the
2-16x11000 23760
whole heat given to the engine is accounted for by the power
developed in the motor cylinder.
If there were no losses of heat to the cylinder, or losses by
throttling during the inlet and transfer of the air from the pump
to the motor or loss of heat from the reservoir to the atmosphere,
then the efficiency of this type of engine would be 30 per cent.
These losses in practice reduce it to 6 per cent. The cycle is a
good one, and under other circumstances is capable of better
things, but it is quite unsuitable for a cold cylinder engine. Cool-
ing and undue resistance are the main causes of the great deficit.
The gases entering the cylinder as flame, in passing through
the inlet chamber expose a large surface to the action of the water
jacket ; the entering currents also impinge against the piston,
causing more rapid circulation than ordinary convection. Both
causes intensify the cooling action of the cylinder walls. In the
engine tested by the author the communicating pipes and the
motor admission valve were much too small ; a considerable loss
of pressure resulted ; although the reservoir pressure was 60 Ibs.,
that in the cylinder never exceeded 48 Ibs. above atmosphere,
showing a loss of 12 Ibs. per square inch from undue resistance.
To enable this engine to realise the advantages of its theory con-
siderable modifications in its arrangements are required. Notwith-
standing all difficulties it has done much useful work, not the least
Gas Engines of Different lypes in Practice 163
notable being the assistance it rendered to Prof. Draper during his
investigation on the existence of non-metallic bodies in the sun's
atmosphere. He used a Brayton petroleum engine for driving his
dynamo machine, and-he stated in his paper that its ease of starting
and almost absolute steadiness in driving were of the greatest ser-
vice to him. In steadiness he states that ' it acted like an instru-
ment of precision.'
F-IG. 48. — Simon Engine.
Simon Engine. — Messrs. Simon, of Nottingham, introduced the
Brayton engine to England in a slightly altered form as a gas
engine. In addition to the ordinary arrangements of the engine
they attempted to gain increased economy, by causing the waste
heat passing into the water jacket, and the heat of the exhaust
M 2
1 64
The Gas Engine
gases, to be utilised in raising steam. They would undoubtedly
have increased the economy of the engine in this manner had
they not turned the steam so raised into the motor cylinder along
with the flame. The cooling of the flame which was serious
enough in the original was thus made worse, and but slight gain
could result, the loss by cooling being slightly exceeded by the
increase of volume due to the steam. Fig. 48 is an external view
of the engine as exhibited at the Paris Exhibition of 1878. A is
the motor, B the pump, and c the added boiler ; the steam was
raised in it and the water jacket. With a suitable arrangement
using the steam in a separate cylinder, doubtless 6 per cent, might
7 ins. dia. of cylinder ; 240 ft. per min. piston speed. Scale -fa in.
FIG. 49. — Diagram from Simon Engine.
be added to the indicated efficiency of the engine, but it is very
questionable if the increased complexity does not entirely destroy
any advantage gained ; it certainly does so in small engines. When
very large engines come to be constructed the complexity would
not be so great and it would be well worth while to use waste heat
in steam raising. The engine, although instructive, did not suc-
cessfully overcome the difficulties which caused the abandonment
of the Brayton as a gas engine. Fig. 49 is a diagram from the
engine which forcibly illustrates the effect of the cooling.
Gas Engines of Different Types in Practice 165
TYPE III.
Engines of this kind resemble those just discussed, in the use
of compression previous to ignition, but differ from them in ignit-
ing at constant volume instead of constant pressure ; that is, the
whole volume of mixture used for one stroke is ignited in a mass
instead of in successive portions.
The whole body of mixture to be used is introduced before
any portion of it is ignited ; in the previous type the mixture is
ignited as it enters the cylinder, no mixture being allowed to enter
except as flame. In Type III. the ignition occurs while the volume
is constant ; the pressure therefore rises ; it is an explosion engine
in fact, like the first type, but with a more intense explosion due
to the use of mixture at a pressure exceeding atmosphere.
The most obvious means of applying the method is that sug-
gested by the Lenoir engine. The addition of a pump taking
mixture at atmospheric pressure, compressing it into a reservoir
from which it passes to the motor cylinder at the increased pres-
sure, seems a simple matter. The igniting arrangements would
act as in the original. As the gases are under pressure, the piston
would take its charge into the cylinder in a smaller proportion of
the forward stroke, and so more of the motor stroke would be
available for useful effect. The diagram such an engine should
produce is seen at fig. 15, p. 50 ; the shaded part is the available
portion, the other part is the pump diagram. The theoretic effi-
ciency of such an engine is as good as the type can give. The
patent list shows that it was the first proposed after Lenoir. Many
such engines have been attempted and have given very good re-
sults economically, but the difficulties of detail are considerable,
the greatest being the necessity for the intermediate reservoir.
Million's patent 1861 proposes to do this, the present author also
constructed one of this kind in 1878, and later one was made by
Mr. Atkinson. The difficulties, however, are too great to allow the
success of small motors on the plan.
Mr. Otto, the first to succeed with the free piston engine, was
also the first to succeed in adapting compression in a reliable
form.
1 66 The Gas Engine
In the third type are included all engines having the following
characteristics, however widely the mechanical cycle may vary :
Engines using a gaseous explosive mixture, compressed before
ignition, and ignited in a body, so that the pressure increases while
the volume remains constant. The power is obtained by expan-
sion after the increase of pressure.
Otto Engine. — In this gas engine, the first to combine the
compression principle with a simple and thoroughly efficient work-
ing cycle, the difficulties of compression are overcome in a strikingly
original manner. To the engineer accustomed to the steam
engine, the main idea seems a bold and indeed a retrograde step.
The early gas engines were moulded more upon the steam engine
model and were to some extent double acting. The Lenoir and
Hugon both received two impulses for every revolution, the
Brayton was single acting, and the Otto is only half single acting.
The steam engine in its advance passed from single to double
acting, and then to four and even more impulses per revolution.
The gas engine, in its progress has in this respect moved backwards,
beginning with double action and then going back. The gain of
this arrangement, however, has completely justified the retro-
gression.
In external appearance the engine closely resembles a modern
high pressure steam engine, the working parts of which are of
somewhat excessive strength ; its motor and only cylinder is hori-
zontal and open ended ; in it works a long trunk piston, the front
end of which serves as a guide and does not enter the cylinder
proper ; the connecting rod communicates between the guide and
the crank shaft, the side thrust is thus kept off the piston and
cylinder proper, which become hot. The crank shaft is heavy and
the fly-wheel a large one ; considerable energy being required to
take the piston through the negative part of the cycle. The
cylinder is considerably longer than the piston stroke, so that the
piston when full in leaves a considerable space into which it does
not enter.
Outside the cylinder, running across it at the end of the space,
works a large slide valve ; it is held against the cylinder face by
a cover plate and strong spiral springs ; it is driven to and fro by
a small crank, on the end of a shaft parallel to the cylinder axis,
Gas Engines of Different Types in Practice 167
I
o
O
1 68 The Gas Engine
and rotating at half the rate of the crank shaft, from which it
receives its motion by bevel or skew gearing .
An exhaust valve, leading into the space by a port, is also
actuated at suitable times from the secondary shaft ; so are the
governing and oiling gear.
The single cylinder serves alternately the purposes of motor
and pump ; during the first forward stroke of the piston, the slide
valve is in such position that gas and air stream into the cylinder
from the beginning to the end of the stroke, the charge mixing as
it enters with whatever gases the space may contain ; the return
stroke then compresses the uniform mixture into the space, and
when the piston is full in, the pressure has increased to an amount
determined by the relative capacity of the space. Meantime the
slide valve has moved to another position, first closing the admission
gas and air ports, to permit of the compression, then bringing on a
cavity in the valve which is filled with flame, when the compression
is completed. The compressed charge therefore ignites and the
pressure rises so rapidly that maximum is attained before the piston
has moved appreciably on its forward stroke (second stroke) :
the piston is thus under the highest pressure at the beginning ol
its stroke and the whole stroke is available for the expansion.
This is the motive stroke. At the end of it, the exhaust valve
opens and the return stroke is occupied in driving out the burned
gases, except that portion remaining in the space which cannot be
entered by th& piston. These operations form a complete cycle,
and the piston is again in the position to take in the charge re-
quired for the next impulse.
The cycle requires two complete revolutions, or four single
strokes.
First out stroke. Charging cylinder with gas and air.
» in » Compressing the charge into the space.
Second out stroke. Explosion impelling piston.
3, in „ Discharging burned gases into atmosphere.
The regulation of the speed of the engine is accomplished by
a centrifugal governor, which is arranged to close a gas supply
valve whenever the speed increases. An explosion is thereby
missed, and the engine goes through its cycle as usual, but as no
Gas Engines of Different Types in Practice 169
170 The Gas Engine
gas is mixed with the air, there is no explosion when the flame
enters, the compressed air merely expanding, giving back to the
piston the energy taken during compression.
When running without load, 8 or even more revolutions may be
made between the impulses, at full load 2 revolutions are made per
impulse. Notwithstanding this irregularity the fly-wheel is so
large that no variation observable by the eye can be seen while
watching the engine.
Fig. 50 is an external elevation of an Otto engine.
Fig. 51 is a sectional plan, and fig. 52 an end elevation showing
exhaust valve lever. A is the water-jacketed cylinder, B the piston
shown full in, c is the compression space or cartridge space as it
is called by Million; i the admission and ignition port, communi-
cating alternately with the gas and air admission port K, and the
flame port L in the slide M ; N is the cover holding the slide to the
cylinder face and carrying in it the external flame for lighting the
movable one in flame port L. The exhaust valve is of the conical
seated lift type and is seen at o; it is driven from the shaft P by
the cam Q and the lever R. The other details are clearly shown
upon the drawing. The ignition valve and governing arrangement
will be described in a subsequent chapter ; here it is sufficient
to state that the governor withdraws a cam actuating the gas
valve s, fig. 52, and so prevents it opening when the piston is
taking in air. When open, the gas passes the valve, then through
a row of holes in the valve port K, streaming into the air and mix-
ing thoroughly with it as it enters the cylinder. To start the
engine, the flame at T is lighted ; the cock commanding the internal
flame being properly adjusted, and the gas turned on, a couple of
turns at the fly-wheel should cause ignition and set the engine
in motion. The larger engines are provided with a second cam,
which keeps the exhaust valve open during half of the compression
stroke and so diminishes the work required to turn round the engine
by hand. When the engine is started the wheel upon the lever is
shifted to the normal cam and the compression then returns to its
usual intensity.
Diagrams and Gas Consumption. — Dr. Slaby, of Berlin, has
made a very careful trial of a four-horse power Otto engine at
Mr. Otto's works, Deutz, in August 1881.
Gas Engines of Different Types in Practice 1 7 1
FIG. 52.— Otto Engine (End elevation).
172 The Gas Engine
The dimensions of the engine are :
Diameter of cylinder . . . . . 171*9 millimetres.
Stroke 340 millimetres.
Compression space .... . . 477° cb. centimetres.
Volume displaced by piston .... 7888 cb. centimetres.
The compression space is therefore o'6 of the volume displaced by
the piston. The results are briefly as follows :
Average revolutions during test . . .1567 per minute.
Power indicated in cylinder .... 5 "04 horse.
Power by dynamometer 4 '4 horse.
Gas consumed in one hour .... 142 '67 cb. ft.
Gas consumed in one hour by igniting flames . 275 cb. ft.
Gas consumption per IHP per hour . .28-3 cb. ft.
Gas consumption per effective HP hour . 32'4 CD- ft.
The composition of the gas used at the Gasmotoren-Fabrik,
Deutz, is given as —
Volumes.
Marsh gas, CH4 34 '4
Ethylene, C2H4 . 3-5
Hydrogen, H 56-9
Carbonic oxide, CO 5 '2
and i cubic metre of it weighs 0*404 kilograms. One pound
weight of it therefore measures 39-6 cubic feet. Deducting the
latent heat of steam produced, i pound weight evolves heat enough
to raise 12,094 Ibs. of water, through one degree Centigrade. It
evolves 12, 094 heat units. From this value, and the experimental
determination of the heat leaving the engine by way of the water
jacket, Dr. Slaby calculates the disposition of 100 heat units given
to the engine as follows :
Work indicated in cylinder i6-o
Heat lost to cylinder walls 51-0
Heat carried away by exhaust 31-0
Heat lost from engine by conduction and radiation . . .2-0
100 'o
The actual indicated efficiency of the engine is therefore 16
per cent, or 0*16.
The temperature of the gases expelled during the exhaust
stroke was determined by carefully protecting the exhaust pipe
Gas Engines of Different Types in Practice 173
from loss of heat by non-conducting material, and then seeing
whether zinc or antimony would melt in it. Zinc melted but
antimony did not ; as the melting point of zinc is 423° C., and the
antimony melting point is 432° C, the temperature of the exhaust
gases is given with great accuracy as between these two tempera
tures. The average composition of the mixture is given as i vol.
coal gas to 1373 vols. of air and other gases. Here Dr. Slaby is
plainly in error, as his own figures conclusively show. The volume
of coal gas taken into the engine at each stroke as measured
by the gas meter is given as 859 cubic centimetres, the total
volume swept by the piston of the engine per stroke is 7888 cubic
centimetres, the volume of the compression space 4770 cubic
centimetres. Now if the gas be introduced into the cylinder
while it is filled completely, space included, with cold gases, at
the same temperature as the gases when measured by the meter,
this figure is correct enough. But the gases are not so introduced,
the space is already filled with exhaust gases at a temperature of
about 400° C. by Dr. Slaby's own determination ; this volume
must therefore be calculated to atmospheric temperature before
an approach to the true ratio can be obtained. Taking atmo-
spheric temperature at 17° C., then 4770 cubic centimetres of
burned gases at 400° C. becomes reduced to 2055 cubic centi-
metres at 17° C; that is, the total charge will consist of 859 cubic
centimetres of coal gas, 7029 cubic centimetres of air, and 2055
cubic centimetres of burned gases from the previous explosion.
The ratio is
coal gas 859 i
air and burned gases 7029 + 2055 10*5
The composition of the charge is more correctly represented
as i vol. of gas to 10-5 vols. of air and other gases. Even here,
however, the dilution is overstated, as it is assumed that the
piston has taken in the charge at full atmospheric temperature
and pressure. But there is some throttling in passing through the
admission valve and port, and also some heating of the air by
striking the piston and cylinder walls. Professor Thurston, in
experiments to be described later on, proves this to be the case,
and shows that the charge is even stronger than has been
calculated.
1 74 The Gas Engine
It has been already proved that in this type of engine, ex-
panding after compression and explosion to the same volume as
existed before compression, the theoretic efficiency is independent
of the temperature of the explosion or the temperature existing
before compression, and depends only upon the volume before and
after complete compression. As the ratio of compression space
to volume swept by the piston is o-6 to i, the volume before
compression is r6, volume after compression o-6.
(v \
The theoretic efficiency is (p. 53) E = i — (-M
\Z0/
and vc is the compression volume, and v0 the volume before com-
/o-6\ '4o8 / i V408;
pression ; in this case E= i — ( — J or i — l-^J
here E = 0-33.
That is, if all the heat were given to the engine at the moment
of complete explosion at the beginning of the stroke, and no heat
were lost to the cylinder during the expansion to the original
volume, then 33 per cent, of that heat would be converted into
indicated work. But the author's explosion experiments give the
factor necessary for correcting this theoretical number (p. 113).
Taking the mixture of i gas to 10 vols. air as nearest, the
efficiency of the gas in it is 0-46 ; that is, during trie time of the
forward stroke, taken as 0*2 sec., i vol. of gas is required to pro-
duce and keep up a pressure which 0*46 vol. would suffice for if
it was all applied to heating and no loss by cooling.
The actual indicated efficiency of the engine using this
mixture and this expansion and compression should be 0-33 x
o'46=o'i52 nearly. That is, the engine should convert 15*2 per
cent, of the heat given to it into work. Dr. Slaby's number, found
by experiment, is 16 per cent. The numbers are exceedingly
close.
The mechanical efficiency of the engine is high, the ratio of
dynamometric to indicated power being 87 to 100, and the friction
of the engine only 0*64 horse
Gas Engines of Different Types in Practice 175
PROFESSOR THURSTON'S EXPERIMENTS ON A 6 HP OTTO
ENGINE.
Dr. Slaby's experiments are exceedingly complete, but Pro-
fessor Thurston in America has made even more extended
measurements.
Messrs. Brooks and Steward made the trials under the direc-
tion of Professor Thurston, at the Stevens Institute of Technology,
Hoboken. The dimensions of the engine are as follows :
Diameter of cylinder .... 8*5 ins.
Stroke . . 14 ins.
Capacity of compression space 38 per cent, of total cylinder
volume.
Not only was the gas entering the engine measured, but at the
same time the air required was measured through a 300 light
meter. So far as the author is aware, this is the only set of
experiments in which this was done ; it is by far the most accurate
way of getting the true proportions of the explosive mixture.
The temperature of the exhaust was measured by a pyrometer,
and the power determined, both by indicator and dynamometer ;
at the same time the heat passing into the walls of the cylinder
was determined by measuring the water heated and estimating
the loss by radiation and conduction.
The total number of revolutions during the various tests were
taken by a counter. Many trials were made under varying con-
ditions of load and mixture used, The following is the best full-
power trial, giving the most economical results :
Average revolutions chiring test 158 per minute.
Power indicated in cylinder . . . . . . 9 '6 horse.
Power by dynamometer 8'i horse.
Gas consumed in one hour 235 cb. ft.
Gas consumption per IHP per hour . . . .24-5 cb. ft.
Gas consumption per effective HP per hour . . 29-1 cb. ft.
An analysis of the gas used during the trials made by Thomas
B. Stillman, Ph.D., is as follows :
176 The Gas Engine
Hydrogen, H 39-5
Marsh gas, CH4 . . . . . . • ':• • 37'3
Nitrogen, N . . ..;.-. 8-2
Heavy hydrocarbons, C2H6, &c. . . t . • • 6 '6
Carbonic oxide, CO 4'3
Oxygen, O . . • I '4
Water vapour and impurities (H2O, CO:,, H2S) . . . 27
lOO'O
One cubic metre of this gas weighs 0*606 kilograms. One
pound weight of it therefore measures 26-43 cubic feet. One
pound when completely burned evolves heat enough to raise 9070
Ibs. water through i° C.
The air necessary to supply just enough oxygen for the
complete combustion of i vol. of this gas is 5-94 vols.
From these values and experiments upon temperature of the
exhaust gases, Professor Thurston estimates the disposition of 100
heat units by the engine as follows :
Work indicated in cylinder 17 'o
Heat lost to cylinder walls . . . . . . . 52-0
Heat carried away by exhaust gases 15-5
Heat lost from engine by conduction and radiation . 15*5
100 'O
The actual indicated efficiency is therefore 1 7 per cent.
The number showing the proportion of heat passing into the
water jacket is also very nearly Slaby's, but the amount expelled
with the exhaust is much understated. The amount lost by radi-
ation is overstated.
The temperature of the exhaust gases, as determined by a
pyrometer placed in the exhaust pipe, varies in the experiments at
full load from 399° C. to 432° C., thus practically coinciding with
Slaby. The ratio of air to gas was found, by actual measurement
of both, to be about 7 to i when the engine was working most
economically. Although with better gas the ratio would be
slightly increased, yet it could not equal that usually given for the
Otto engine, 10 to i or thereabouts.
The ratio is commonly obtained from a measurement of the
gas consumption alone, the air being reckoned as the volume of
the piston displacement, less the measured amount of gas. This
is not an accurate method, for the reason already stated.
Gas Engines of Different Types in Practice. 1 77
If the mixture filling the cylinder mingles with the burned
gases filling the compression space, then the average composition
of the charge is i vol. coal gas to 9'! vols. of other gases.
178 The Gas Engine
Fig. 53 is a fair sample of the diagrams obtained during Pro-
fessor Thurston's tests while the engine was giving full power.
The piston while moving from the point i to the point 2 takes
in the charge ; the pressure in the cylinder falls below atmo-
sphere as the piston approaches the end of its stroke. This is
due to the resistance of the valve port to entering air and
gas. The piston returns from 2 to 5 (ist in-stroke) compress-
ing the charge, the pressure increasing to atmosphere at the
point 3, the compression being complete at the point 5 ; the
ignition then occurs, and the pressure and temperature rapidly
rises as the explosion progresses; the temperature does not
attain its maximum till the piston has moved forward a little and
has reached the point 6. From that point to 7, when the ex-
haust valve opens, the expanding line is as nearly as possible
adiabatic. The temperatures are marked at each point of the
diagram. The return stroke from 2 to i discharges the products
of combustion. This is the second in-stroke, completing the
cycle and leaving the engine in position to again take in the
charge.
The diagram shows the whole changes occurring during two
complete revolutions of the machine while fully loaded. Fig. 54
shows what occurs when the governor acts, when the engine is at
less than full load. The smaller diagram, B, is the normal one,
and the larger, A, the intermittent one ; the gas has been com-
pletely cut off for several strokes, and so the hot burned gases in
the compression space have been completely discharged and re-
placed by pure air at a temperature not far removed from atmo-
spheric ; the explosion then causes a higher pressure by nearly half
an atmosphere, although the maximum temperature is less than in
the usual case.
The temperature of the charge before explosion being less, a
smaller increase is required to produce a given increase of pressure.
Professor Thurston calculates that the heat accounted for by the
diagram is 60 per cent, of the total heat supplied to the engine ;
the deficiency he attributes to the phenomena of dissociation,
which prevents the complete evolution of the heat at the highest
temperature, but permits further combustion when the temperature
falls. The amount of gas required to run at full speed, 166 revo-
Gas Engines of Different Types in Practice 179
lutions per minute without any load, was found to be from 50 to
70 cubic feet per hour.
Other tests of Otto Engine. — The experiments of Dr. Slaby and
Professor Thurston upon the Otto engine are by far the most
complete which have yet been made to the author's knowledge.
N 2
1 80 The Gas Engine
Some tests given in Schottler, however, will be quoted. A four
HP engine was found to consume as a best result 32-4 cubic
feet of gas per brake HP per hour in Altona, giving at the time
3-96 HP on the dynamometer. Another consumed 337 cubic
feet per brake HP per hour in Hanover, giving 4-95 HP on
the dynamometer; to drive the last engine at 160 revolutions per
minute without load required 41-3 to 43-4 cubic feet of Hanover
gas.
A two-horse engine, tested by Erauer and Slaby, Berlin, gave
2-28 brake HP, using 35-3 cubic feet per brake HP per hour.
In this country the coal gas in common use is of higher heat-
ing value than that used on the Continent and in America \ ac-
cordingly the gas required per HP is less, but the efficiency is
almost identical.
Experiments made upon an 8 HP Otto engine by the Philo-
sophical Society of Glasgow in 1880, showed a consumption of
22 cubic feet of Glasgow gas per indicated HP, giving 9 HP upon
the dynamometer, and 28 cubic feet per dynomemetric horse.
Experiments made at the Crystal Palace Electrical Exhibition,
in 1881, with a 12 HP engine gave a maximum brake power of
18-3 HP, with a gas consumption of 237 cubic feet per IHP, and
29-1 cubic feet per brake HP. With a two-horse engine, 2*87
brake horse was obtained upon 33-4 cubic feet per horse hour,
and 27-9 cubic feet per indicated horse hour.
The consumption running without load does not seem to have
been taken in these tests.
The author has taken the consumption of a two-horse engine
running without load in London, at 160 revolutions per minute, as
32 cubic feet per hour, and a 3-5 horse engine without load at
1 66 revolutions per minute as 43 cubic feet per hour.
The Messrs. Crossley give the following as the results with
their new Otto twin engine rated at 12 HP :
Power by dynamometer 23 horse.
Power indicated in cylinders . . . .28 horse.
Gas consumption per indicated HP . . . 20 cb. ft. per hour.
Gas consumption per effective HP . . . 24*3 cb. ft. per hour.
Total consumption at full power .... 560 cb. ft. per hour.
Total consumption when lunning without load at
1 60 revs, per minute 100 cb. ft. per hour.
Gas Engines of Different Types in Practice 181
£
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1 82 The Gas Engine
These results are obtained using Manchester gas.
Mr. G. H. Garrett has made a trial with an 8 HP Otto engine
in Glasgow, the diagram and particulars of which are given on
fig- 55-
Summary of Experiments. — From these numerous and careful
experiments, conducted quite independently of each other by
many observers, it may be taken as abundantly established that
the Otto engine is a great advance in economy and certainty of
action upon any gas engine preceding it. On the Continent and
in America the consumption per horse power hour is, on the
whole, greater than in Britain ; this is due not to any appreciable
difference in the efficiency of the engines made here, but to the
better gas common in this country.
Calculations of the efficiency attained in some of the later engines
in England, show that as much as 18 per cent, of the heat is con-
verted into work as shown by the indicator. Dr. Slaby's value is
1 6 per cent., and Professor Thurston's 17 per cent. All observers
agree that the heat liberated at the moment of completed explosion,
that is, of highest temperature, is roughly one-half of the total heat
present as coal gas, the remaining half being evolved during the
expansion period. Professor Thurston gives the heat of the ex-
plosion as 60 per cent, of the total heat present, Dr. Slaby as 55
per cent. The author's experiments upon the heat evolved by
the explosion of different mixtures of gas and air, show heat
accounted for by the explosion as ranging from 50 to 60 per cent.,
agreeing with the determinations of Bunsen, Him, Mallard and
Le Chatelier, and Berthelot and Vieille. It may therefore be
considered as absolutely proved that this suppression of heat at
explosion, and its evolution during expansion, is a phenomenon
inherent in ever)7 explosive mixture, however made — a thing, in
fact, from which there is no escape. In whatever way an engine
be made, if it explodes or burns a mixture of any inflammable
gas with any mixture of gases containing oxygen, then this slow
combustion or, as the Germans have it, nachbrennen (after-burn-
ing) is unavoidably occasioned. Knowing this, and knowing of
Him, Bunsen, and Mallard and Le Chatelier's work long prece-
dent to Dr. Slaby's report, it is surprising to find so able and
learned a scientist quoted as stating that in the Lenoir engine
Gas Engines of Different Types in Practice 183
the whole heat was evolved at the moment of complete explosion.
In the Lenoir, as in every other gas engine which has ever
been constructed, not more than one-half of the whole heat of
the gas present is then evolved, the remaining heat being evolved
on the expanding stroke.
Schottler falls into the same error, and, -although mentioning
Wedding's statement of Bunsen's law of dissociation, shows that
he rejects it when he assumes that the whole heat is evolved. A
very cursory examination of the Lenoir diagram would at once
prove to Prof. Schottler that Lenoir did not succeed in so
escaping the laws of nature ; had he done so, there would have
been no necessity for our modern improvements.
The consumption of continental gas may be taken as varying
between 32 cb. ft. and 35 cb. ft. per effective HP per hour, and
about 28 cb. ft. per IHP per hour.
In Britain it may be taken as ranging from 24 cb. ft. pet
effective HP to 33 cb. ft., and 20 to 24 cb. ft. per IHP per hour,
depending upon the quality of gas used and on the dimensions
of the engine tested. Other things being equal, better results
are obtained with large engines. The theoretic efficiency is con-
stant for both large and small engines where the same compression
is in use, but the loss of heat from the explosion to the sides of
the cylinder is less in the large engines, due to the diminished
surface exposed in proportion to the volume used. The effect is
to increase the efficiency of the gas in the mixture used, a
smaller quantity being necessary to make up for the loss of
heat,
The indicator diagrams prove the very efficient nature of the
Otto cycle. The great simplicity attained by the alternate use of
the cylinder as pump and motor diminishes the number of valves
necessary, and secures the minimum resistance to the entering
gases, while entirely preventing any loss due to ports, in trans-
ferring the gases from one cylinder to another. The carrying out
of the cycle is mechanically almost perfect, no work being spent
which is not included in the theory. Again, the piston is full in
at the moment of ignition and is almost at rest ; the heat, pro-
ducing maximum temperature, is therefore added ' at nearly
constant volume. The highest pressure which the gas present is
1 84 The Gas Engine
capable of producing is therefore attained at the beginning of the
stroke simultaneously with the highest temperature ; the succeed-
ing expansion is then very rapid, and so no unnecessary waste of
heat occurs, the temperature being rapidly depressed by work
being done. The united effect of all the arrangements is seen in
a diagram which is almost theoretically perfect ; the only de-
duction from theory is due to the unfortunate property of explo-
sive mixtures of continued combustion after explosion. And
this reduces the theoretic efficiency to one-half in practice. The
theoretic efficiency of all Otto engines, of whatever dimension, is
o\33, as the compression space in all cases bears nearly the ratio
of o-6 to i'o when compared with the cylinder volume which is
swept by the piston. The actual indicated efficiency is very
nearly one-half of that number.
If combustion by any means could be made complete at the
highest temperature and pressure at the beginning of the stroke,
instead of continuing as it does well into the expansion stroke,
then greatly increased economy would result, and in large engines
theory might be very nearly approached.
This point will receive further discussion later on.
Clerk Engine. — Otto's method is probably the readiest and
easiest solution of the problem of attaining in a practicable
manner the advantages of compression ; in some points, however,
the advantages are accompanied with compensating disadvantages.
Only one impulse for every two revolutions is obtained ; the
engine is therefore stronger and heavier than need be if impulse
every revolution were possible. It is also more irregular in its
action than more frequent impulses would give.
The Clerk engine was invented by the author with the view of
obtaining impulse at every revolution, while getting at the same
time the economy due to compression.
At first blush it seems a very simple matter to make a com-
pression gas engine to give an impulse for every revolution ; this
was the author's opinion when he commenced work for the first
time upon gas engines using compression in October 1876. Since
then he has had occasion to modify the opinion : the difficulties
are very great ; any engineer who doubts this will speedily be
convinced upon making the attempt.
Gas Engines of Different Types in Practice 185
It was not till the end of 1880 that the author succeeded in
producing the present Clerk engine ; before that time he had
several experimental engines under trial, one of which was ex-
hibited at the Royal Agricultural Society's show at Kilburn in
July 1879. This engine was identical with the Lenoir in
idea, but with separate compression and a novel system of
ignition.
The Clerk engine at present in the market was the first to
succeed in introducing compression of this type, combined with
FIG. 56.— The Clerk Gas Engine.
ignition at every revolution ; many attempts had previously been
made by other inventors, including Mr. Otto and the Messrs.
Crossley, but all had failed in producing a marketable engine.
It is only recently that the Messrs. Crossley have made the Otto
engine in its twin form and so succeeded in getting impulse at
every turn.
In the Clerk engine the whole cycle is completed in one re-
volution, and an impulse given to the crank on every forward
stroke of the piston, when working at full power.
The engine contains two cylinders, one for producing power,
1 86 The Gas Engine
the other for taking in the combustible charge and transferring it
to the power cylinder. At the end of the motor cylinder is left
a compression space of a conical shape, and communicating with
the charging or displacing cylinder by a large automatic lift-valve
opening into the space ; at the other end of the cylinder are placed
V-shaped ports opening to the atmosphere by the exhaust pipe ;
the motor piston, when near its outer limit, overruns these ports
and allows the cylinder to discharge. The pistons are connected
in the usual manner by connecting rods, the motor to the main crank
of the engine, the displacer to a crank pin in one of the arms of
the fly-wheel ; the displacer crank is in advance of the motor crank,
in the direction of motion of the engine, by a right angle. The
displacer piston on its forward movement takes in its charge of
gas and air, and has returned a fraction of its stroke when the
motor piston uncovers the exhaust ports. While crossing the centre,
opening and shutting these ports the displacer piston has moved
in almost to the end of its cylinder, discharging its contents
into the space and forcing out at the exhaust ports the products of
the previous ignition. The proportions of the two cylinders are so
arranged that the exhaust is as completely as possible expelled,
and replaced by cool explosive mixture, which thoroughly mixes
with any exhaust remaining, cooling it also to a considerable
extent. Care must be taken in the arrangement of the parts
that an excessive volume is not sent from the displacer,
otherwise it may reach the exhaust ports and gas discharge
unburned.
The return stroke of the motor piston now compresses the
mixed gases, and when at the extreme end, the igniting valve fires
the mixture, the piston moves forward under the pressure thereby
produced, till the opening of the exhaust ports causes discharge
and replacement as before. In this way an impulse is given at
every revolution, and the motive power applied to greater advantage.
The motor cylinder is surrounded by water for cooling, but this
is unnecessary with the displacer, as it uses only cool gases. The
pressures used are high, so that both motor piston and its connec-
tions are made very strong ; the pressure on the displacer piston
is very little, so the connections are light. It is not a compressing
pump, and is not intended to compress before introduction into
Gas Engines of Different Types in Practice 187
the motor, but merely to exercise force enough to pass the gases
through the lift valve into the motor cylinder, and there displace
the burnt gases, discharging them into the exhaust pipe. The
pressure to be overcome is only that due to resistance in the
exhaust pipes and the lift valve.
The inlet valve for gas and air is also automatic ; its seat is of
the usual conical kind but somewhat broad. A gutter runs round
the centre, having small holes bored through to a recess behind,
FIG. 57.— Longitudinal Section of Clerk Gas Engine.
which communicates with the gas supply pipe. The suction lifts the
valve to a certain height, and, as the gases enter, the air flows past
the holes and becomes thoroughly impregnated with gas, the
extent being determined by the number of holes and the propor-
tion of their area to the total area of the valve opening. The
upper valve is made heavy to withstand the maximum pressure of
the explosion ; both valves are arranged so that the guide forms
1 88 The Gas Engine
a piston working in an air cylinder, so arranged as to check
the fall of the valve before touching the seat, and so prevent any
disagreeable rattle.
Description of the Drawings. — Fig. 56 is a general view of the
engine. Fig. 57 a longitudinal section. Fig. 58 a sectional plan.
In these drawings all the essential parts of the engine are repre-
sented ; the sectional plan (fig. 58) shows the two cylinders,
motor A and displacer B, in which work the pistons c and D
suitably connected to cranks not shown in the drawing, but on a
common crank shaft. The motor crank is double and of great
strength ; the displacer crank pin is fixed into an arm in the fly-
wheel, and in the direction of motion of the engine is a half right
angle or quarter circle in advance. The motor piston is shown at
its extreme out-stroke, having passed over the exhaust ports E E1,
the piston thus serving as its own exhaust valve, and dispensing
with any other, as shown ; the displacer piston has moved half in
and discharged a portion of the contents through the valve F
(more distinctly seen in the other section, fig. 57) into the conical
space G, which is so proportioned that the entering gases push
before them the burned gases through the ports referred to, but
without following them into these ports. By the continued move-
ment, all the gases in B pass into A and the space G; the capacities
of the two cylinders are so related that as much as possible of the
burnt gases is discharged into the atmosphere, but without carrying
away any of the fresh mixture containing unburned gas; this neces-
sitates the mixture next the piston being somewhat more dilute
than that next the inlet valve, but the commotion occasioned by
compression so far equalises this undesirable state of things that at
half in-stroke the mixture in its weakened portions is quite capable
of inflammation by a light or the electric spark. The piston D
having completed its in-stroke, c has passed over the discharge
ports and compresses the contents of the cylinder into the space G;
when full in and therefore completely compressed, the slide valve
M has moved into such a position as to ignite the mixture ; the
maximum pressure being attained very rapidly and before the
piston can move appreciably on its out-stroke, the piston is impelled
forward under the pressure produced until it reaches the ports E E1,
when the contents are rapidly discharged, and the interior and
Gas Engines of Different Types in Practice 189
190
The Gas Engine
exterior pressures equalised. Meantime the piston D being in
advance of the motor has moved to the end of its stroke and is
beginning to return, it has charged the cylinder B with a mixture
of gas and air from the automatic valve H (fig. 57), the commu-
nication being made by the pipe w (fig. 58). In the seat of this
valve are bored a number of small holes passing into the annular
space K K1 (fig. 57), which communicates with the gas cock L (fig.
58) through the passage shown, in which is situated the lift-govern-
ing valve, not seen. Under the deficit of pressure caused by the
Upper lift valve.
.
jjj- - ^ Quieting piston.
Lower lift valve.
- - Gas channel.
Quieting piston.
5
FIG. 59.— Section of Lift Valves. Clerk Engine.
movement of the displacing or charging piston, the valve is lifted
and the exterior atmosphere rushes through, at the same time the
gas passing through the holes mixes with it thoroughly, the pro-
portion being determined by the relative areas of the holes and
the space available for air by the lift of the valve.
The gases in B are under some slight compression before the
complete discharge of A, but not sufficiently great to cause any
material resistance ; so soon as the pressure under the valve F is
slightly in excess of that above it, then it lifts and the gases pass
into G. The passage from the valve, which may be called the
Gas Engines of Different Types in Practice 191
upper lift valve, is more clearly seen in fig. 57 : the igniting hole
is shown at N, and communicates at the proper time with flame in
the cavity o, which has been ignited at the exterior flame P, from
a Bunsen burner (fig. 58).
The two automatic valves charging the displacer cylinder and
discharging into the motor cylinder are provided with quieting
pistons, cushioning the blow on the valve seat and preventing
rattle ; they are similar to the dash pot contrivances used on
Corliss' steam engines to check the snap of the steam valves, but,
unlike them, are attached directly to the valve, instead of to the
valve spindle and guide. The arrangement is very clearly seen at
fig. 59 : the lower valve has no spring, it returns to its seat by its
own weight ; but the upper valve requires to act more quickly
and is pulled down by a spring.
The piston attached compresses the air before it, and the
valve strikes its seat rapidly but without jar or recoil.
The igniting slide, M, is driven from an eccentric on the crank
shaft through a bell crank and guide.
Diagrams and Gas Consumption. — The following tests give
the latest results from the Clerk engine ; they are the usual trials
TESTS OF THE CLERK ENGINES OF VARIOUS POWERS.
2 HP
4 HP
6 HP
8 HP 12 HP
Diameter of motor cylinder
5 ins.
6 ins.
7 ins.
8 ins.
9 ins.
Stroke
8 ins.
10 ins. 12 ins.
16 ins.
20 ins.
Diameter of displacer cylinder .
6 ins.
7 ins. 7i ins.
10 ins.
10 ins.
Stroke 19 ins.
ii ins. 12 ins.
13 ins.
20 ins.
Average revs, permin. during test 212
190
146
142
132
Average pressure (available) in j
motor cylinder in Ibs. persq. in.
Power indicated in motor cylinder
43-2
3-62
8-68
53'2
9^5
60-3
17-38
64-8
27-46
Power by dynamometer
270
5 '63
7 '23
13-69 23-21
Gas consumption in .cb. ft. per
IHP per hour
29-8
24-19
24 '3
20-94
20-39
Gas consumption per brake HP
hour
40*0
37 '3
30-42
26-58
24-12
Max. pressure of explosion in Ibs.
per sq. in. above atmos.
155 Ibs.
236
195
195
238
Pressure of compression in Ibs.
per sq. in. above atmos.
38 Ibs.
55
48
49
57
Displacer resistance .
0-40
o'8o
0-86
1-50 1 2'OO
Gas consumed per hour by each
engine at speed without load .
40 cb. ft.
58 cb. ft.
57cb.ft.
70 cb. ft. 90 cb. ft.
192
The Gas Engine
made by Messrs. L. Sterne and Co. on all engines before leaving
the works, and therefore represent fairly the economy to be
expected from these engines in ordinary work. They are from
2, 4, 6. 8, and 12 HP engines (nominal). The trials were made
during 1885 at the Crown Iron Works, Glasgow, under the
direction of Mr. G. H. Garrett.
Figs. 60, 6 1, 62 are fair samples of the diagrams taken during
the tests. Figs. 63 and 64 are diagrams from the displacers
showing the dispiacer resistance.
CC
Nominal HP, 6 ; diam. of cylinder, 7" ; length of stroke, 12" ; No. of revs. 146 ; in-
dicated HP, 9-05 ; consumpt. per IHP, 24-30 cb. ft. ; consumpt. loose, 57 cb. ft. ;
brake HP, 7*23 ; consumpt. per BHP, 30-42 cb. ft. ; mean pressure, 53-2 Ibs. ; max.
pressure, 195 Ibs. ; press, before ignition, 48 Ibs. ; scale of spring, ^" per Ib.
FIG. 60.— Diagram from Clerk Gas Engine, 6 HP.
Calculating from these diagrams the actual indicated efficiency
it comes to 16 per cent, of the total heat given to the engine.
The compression space in the Clerk engines is as nearly as
possible one-half of the volume swept by the piston from the
exhaust port to the end of its stroke. The theoretic efficiency is
therefore
The compression is higher, and therefore the theoretic efficiency
Gas Engines of Different Types in Practice 193
of this engine is higher than the Otto, but the difficulties of pro-
portioning the two cylinders of the Clerk engine cause a small
loss of unburned gas at the exhaust ports, so that the actual
efficiency is similar to that of Otto.
The mixture sent from the displacer cylinder into the motor
and the space at the end of it, contains 8 vols. of air with
i vol. of coal gas, but on passing through the upper lift valve
and mixing to some extent with the exhaust there contained, it
is somewhat diluted ; the heat acquired by contact with the
products of combustion and with the sides of the cylinder expands
the entering gases, and a temperature of not less than 100° C. is
Nominal HP, 8 ; diam. of cylinder, 8" ; length of stroke, 16" ; No. of revs. 142 ;
indicated HP, 17*38; consumpt. per IHP, 20*94 cb. ft. ; consumpt. running light
per hour, 70 cb. ft. ; brake HP, 13*69 ; consumpt. per BHP, 26*58 cb. ft. ; mean
pressure, 60*3 Ibs. ; max. pressure, 195 Ibs.; pressure before ignition, 49 Ibs. ; scale
of spring, ^' per Ib.
FIG. 6 1.— Diagram from Clerk Gas Engine, 8 HP.
attained before the compression commences. The result of this
is, that the displacer gases, being expanded, expel more of the
exhaust gases through the discharge ports than would appear
from the volume swept by the displacer piston. This volume is
equal to the volume swept by the motor piston, from closing of
the exhaust ports to complete in-stroke. If no expansion and no
mixing occurred, the exhaust gases contained in the compression
space would remain in front of the cooler explosive charge ; but
the heat increases the volume at least one-third, so that the
o
194
The Gas Engine
volume occupied will be i^ times the volume swept by either
piston. The volume of cylinder plus space is i^ vol. of cylinder,
so that the actual exhaust gases present are | vol., or -^ of the
total gases present. But mixing must occur to a considerable
extent and be made very complete on the return stroke during
Gas Engines of Different Types in Practice 195
compression. The result of all this is the production of an explosive
mixture which is explosive in every part of it, and of an average
composition of one volume of coal gas in ten of the mixture.
The proportion of burned gases present is very slight ; the only
reason why any should be left is the necessity of preventing any
u
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.2
Q
appreciable discharge of unburned gas at the exhaust ports. The
mixture used is a comparatively rich one.
Tangye Engine. — Messrs. Tangye, of Birmingham, have pro-
duced an engine in which compression of the kind common to the
third type is used and an ignition is obtained for every revolution
o 2
196 The Gas Engine
when at full power. It is Robson's patent and contains only one
cylinder. All the necessary operations of charging, compressing,
and igniting are fulfilled with one cylinder ; it is arranged as in an
ordinary steam engine. The front end of the cylinder unlike the
Otto and Clerk engines is closed, a piston rod, cylinder cover,
and stuffing box being provided, as in steam. The front end of
the cylinder serves for charging, the back end for compression
and explosion.
There is a compression space at the back end of the cylinder as
in the other engines.
The action is as follows. During the return stroke, gas and
air mixture is drawn into the front end of the cylinder at atmo-
FIG. 65. — Robson's Gas Engine.
spheric pressure, through an automatic valve. The next out-stroke
compresses the mixture into a large intermediate chamber at a
pressure of not more than five Ibs. per sq. in. above atmosphere.
When full out and the exhaust ports therefore open, this pressure
lifts a valve leading into the compression space of the engine, dis-
charging before it the gases contained in the cylinder through the
exhaust valve and filling the cylinder and space with explosive
mixture. This reduces the pressure in the intermediate reservoir
to atmosphere so that the next in-movement of the piston com-
presses the explosive mixture upon one side of the piston and takes
in fresh mixture on the other side.
Gas Engines of Different Types in Practice 197
When compression is completed the igniting valve acts and the
explosion impels the piston ; so soon as the exhaust ports open, the
pressure falls to atmosphere, and then the reservoir pressure being
superior to that in the cylinder, the automatic valve acts and the
fresh charge enters.
Thus an explosion is obtained at every revolution by using the
front end of the cylinder as displacer and storing up the pressure
in an intermediate reservoir.
The governing is managed by cutting off gas supply, but is
hampered considerably by the intermediate chamber. Fig. 65
is an external view of the engine, which is exceedingly neat and
of substantial workmanship.
The Stockport Engine. — This engine is similar to Robson's
FIG. 66. — The Stockport Gas Engine.
in theory but the front end of the cylinder is not used for charg-
ing, the piston being made a double trunk with the crank be-
tween, and one end and one cylinder being motor, the other end
and the other cylinder being displacer. Compression occurs in
the motor cylinder. Fig. 66 shows the external appearance. The
valve arrangements differ from those of Messrs. Tangye. It is
made by Messrs. Andrew, of Stockport.
Atkinson's Differential Engine. — The description of engines of
this type would be incomplete without mention of this engine,
exhibited at the Inventions Exhibition for the first time in 1885.
It is exceedingly ingenious and quite novel.
198 The Gas Engine
Fig. 67 is an elevation, fig. 68 a section, and fig. 69 a plan.
The action is very clearly seen from the different positions on fig.
70.
The same cylinder serves for all purposes of the cycle ; two
trunk pistons, working in opposite ends of it are connected to
ELEVATION
FIG. 67. — Atkinson's Differential Gas Engine.
the levers and from thence to the crank shaft by the connecting
rods. The short rods cause the necessary actions.
In the first position, fig. 70, the pistons are at one extreme of
their stroke, and are just beginning to separate. The charge of gas
Gas Engines of Different Types in Practice 199
and air enters between them through the automatic lift valve, and
in position 2, the charge has entered and the further movement
of the piston is about to close the port leading to the admission
and exhaust valves. The compression thus commences and in
position 3 it is completed. The ignition occurs and the pistons
SECTION
FIG. 68. — Atkinson's Differential Gas Engine.
now rapidly separate, the exhaust port being uncovered and the
discharge commencing in position 4. By this clever method
the whole operations of admission, discharge, ignition, and expan-
sion are performed in the single cylinder with only two automatic
200
The Gas Engine
FIG. 69.— Atkinson's Differential Gas Engine.
Yi
FIG. 70.— Atkinson's Differential Gas Engine-
Gas Engines of Different Types in Practice 201
valves which are never exposed to the pressure of explosion, the
pistons acting in some part as valves and uncovering the exhaust
and inlet ports when required. In the other extreme position they
also act as valves, the outside piston uncovering the igniting port
at the correct time. Sufficient experience has not yet been accu-
mulated with this engine to speak positively as to its performance.
To the author, the principal disadvantage appears to lie in a com-
pression space of diameter so great, in proportion to depth, that the
ratio of cooling surface to volume of hot gases is largely in excess
of that common to other engines. This disadvantage will dimmish
the economy which the great expansion would otherwise give.
2O2 The Gas ~Engine
CHAPTER VIII.
IGNITING ARRANGEMENTS.
HOWEVER perfect the theoretic cycle of an engine, or however
admirable is its construction, in the absence of a good igniting
valve the skill and energy expended is of po avail. The engine
is a useless mass of metal requiring power to move itself rather
than furnishing power to set other machines in motion.
In the earlier stages of gas engine manufacture, the igniting
method has been the most fruitful source of annoyance and diffi-
culty ; even yet, after many years of engineering experience, the
igniting valve is still the initial difficulty which the inventor must
overcome before he gets the opportunity of testing his theories £>f
heat and work in a moving machine. Quite a number of wit-
nesses, in the shape of unworkable gas engines, in many engineers'
workshops throughout Britain, attest silently but emphatically the
difficulties of the igniting valve.
The problem is by no means a simple one, and the care
lavished, upon its solution would not be suspected on inspection
of the igniting gear of any good modern engine. Much has been
done, but much still remains yet to be accomplished before flame
is as completely and effectively under control as steam.
In the noncompression engines the problem is comparatively
simple — to inflame a volume of explosive mixture enclosed in
a cylinder, so that the explosion is confined within the cylinder,
and no communication is open to atmosphere. This is to be re-
peated regularly and with certainty at rates varying from 60 to 150
times per minute, depending upon the speed of the engine. In
the earlier trials, what may be called the touch hole method
naturally suggested itself; the piston after taking in its charge,
crossed a small hole and sucked a flame through it into the cylin-
Igniting Arrangements 203
der, the hole being either small enough to occasion no substantial
loss of pressure upon explosion, or covered by a small valve closing
with the pressure from the interior. This is the earliest flame
method. Then comes the idea of using the electric spark, and so
completely closing up the cylinder, and, later on, a return to flame,
using a double flame, one to ignite an intermediate one, and
the intermediate flame carried in a pocket or hollow cock to the
mixture. Then the idea of spongy platinum suggested by the
well-known Doebereiner's Hydrogen lamp. Later on the heating
of metal tubes or metal masses and the ignition of the gases by
contact with them. Then electrical ignition again, but this time
by heating a platinum wire to incandescence. All those methods
were proposed and to some extent practised long before gas
engines appeared in any commercially successful form.
Ignition methods may be classed in four distinct groups.
(1) Electrical methods.
(2) Flame methods.
(3) Incandescence methods.
(4) Methods depending on ' Catalytic ' or chemical action.
(i) ELECTRICAL METHODS.
Spark Method. — The use of the electric form of energy seems
at first sight a very convenient and easy method of getting an in-
tense heat at any desired time and in any desired spot in the
interior of a cylinder. The electric spark has long been used by
chemists to explode the contents of the eudiometer in which gas
analysis is effected ; and the platinum wire rendered incandescent
by the current from a battery has long been familiar to experi-
menters and is used by them for many purposes. The spark
method was used in the Lenoir engine. A Bunsen's battery, a
Rumkorff induction coil, and a commutator or distributor, is
required in addition to the insulated points between which the
spark passes in the interior of the cylinder.
Fig. 71 is drawn to show clearly the general arrangement.
The Bunsen's battery A generates the current, which passes by the
wires to the coil B, from which the intensity current passes to the
insulated points D D by way of the distributor c. The negative
pole of the coil is permanently connected to any part of the metal
204
The Gas Engine
work of the engine ; the igniting points D, D, consist of porcelain
plugs seen on a larger scale at E. The porcelain is firmly
cemented into the brass nut i, and the wire 2 which passes through
a hole in the plug terminates outside in the connecting screw 3,
and inside is bent over the end of the plug ; the other wire 4,
passes through another hole in the plug, is bent over in the inside
lying near the wire 2 but not touching it, it then passes through
the side of the plug touching the metal of the nut. When the
nut is screwed into position the one wire is in metallic connec-
tion with the cylinder of the engine, and the other is insulated
from it.
FIG. 71. — Ignition Arrangements Lenoir Engine.
The distributor c consists of an insulated metallic arm i rota-
ting on the end of the crank shaft over the insulated ring 2, which
is connected to the positive pole of the coil. Two insulated seg-
ments 3, 4, are connected by wires to the igniting plugs D, D ; in
rotating, the arm i comes alternately over 3, 4, and it is within
sparking distance of the ring 2 as well as the segments ; the sparks
pass alternately to the segments and thence alternately to the
opposite ends of the cylinder. The ebonite disc carrying the seg-
ments and ring is so adjusted that the spark begins to pass at either
end, just as the admission valve closes. If it passed too soon the
Igniting Arrangements 205
explosion would occur before the admission valve closed, and
therefore would partly be lost, and at the same time would make a
disagreeable noise. If it is passed too late, power is lost, because
the piston is at its most rapid rate of movement and is reducing
the pressure of the cylinder contents uselessly.
Notwithstanding the most careful adjustment, some time
elapses between the closing of the admission valve and the explo-
sion. When all is in good order this arrangement works very well,
but should the insulation be disturbed and any short circuiting
occur, the spark fails to pass between the points in the interior of
the cylinder and a missed or late ignition results, This often
happens in starting the engine when it is cold; the first few explo-
sions cause a condensation of water upon the points and the spark
then fails, the current passing through the water film from wire to
wire without spark. The igniters then require to be uncoupled
and dried. To reduce this trouble, the points are kept towards
the top of the cylinder in the end covers so that any water or oil
drainage may flow down and leave them dry. The difficulties of
insulation, coil and battery, are so great that they did much to
prevent the use of the Lenoir engine ; unless the machine fell into
intelligent hands it was sure to go wrong and give trouble.
The spark method has never been applied to compression
engines as the compression increases all difficulties. The Lenoir
igniting plug, or ' inflamer ' as it was called, if put in a compression
engine leaks badly and cannot be got to act efficiently. Many
specifications of compression and other engines state that ignition
is accomplished by the electrical spark, but the Lenoir engine alone
attained any success.
Incandescent Wire Method. — This method very naturally suggests
itself as a solution of the difficulties of the high tension spark; the
coil is dispensed with and the current from the battery is applied
directly to heat a thin platinum wire. The difficulty of insulating is
very slight. The tension being low it is a matter of indifference
whether the insulating material is wetted or not. The wire being
constantly at a red heat cannot remain at all times in the cylinder,
but is put into communication with it at proper times by means of
a slide valve. Fig. 72 is a drawing of an igniting slide of this kind,
as used by the author in experimental work. It acts very well in-
2O6
The Gas Engine
deed. The screw i carries the insulated rod 2, insulated by means
of asbestos card-board packed into the space and screwed down
firmly by the screw 3. The other wire is screwed into the metal
and so is in metallic connection with the metal work of the
engine. One wire from the battery connects to any portion of the
engine ; the other is insulated. The platinum wire 4 is thus kept
continually at a red heat, and the slide 5 moving at proper times
causes the gases to be ignited to flow into the chamber containing
the platinum spiral, by the hole 6, and so causes the explosion.
FIG. 72. — Electrical Igniting Valve (Clerk).
Incandescent Platinum Wire.
There is only one precaution required in using this. The battery
must not be too powerful ; if the wire is heated by it to near its
fusing point, then the further heat supplied by successive explo-
sions may cause its destruction. It requires to be kept at a good
red heat and no more when open to the air : when closed up and
in contact with the hot gases it will then become almost white hot ;
anything above this may fuse it. The battery is of course at all
times a source of care ; as it requires to be often renewed, it is only
for experimental work that this arrangement answers well. In the
hands of the general public it would come to grief. Hugon and
Igniting Arrangements 207
many others proposed similar arrangements, but they do not appear
to have worked them out.
Arc Method. — There is another electrical method. A small
dynamo attached to the engine keeps up a continuous current and
heavy platinum points in communication with the cylinder carry
the arc. This is difficult, however, as the points constantly volatilize
and require frequent renewal. This method has never come into
practical use ; it is described several times in specifications.
(2) FLAME METHODS.
The earliest really efficient igniting valve is that described by
Barnett in his specification of 1838. It is the parent form of
the most extensively used valve, the 'Otto.'
Barntifs Igniting Valve. — Fig. 73 shows a vertical section and a
plan of this valve. It consists of a conical stopcock with a hollow
plug; the shell contains two ports, i and 2 — i open to the atmosphere
and 2 communicating with the cylinder. The plug of the cock has
one port, 3, so arranged that it may open on the atmosphere port or
the cylinder port in the shell, but cover enough being left to pre-
vent it opening to both at the same time. In turning round it
closes on me atmosphere before opening to the cylinder.
A gas jet burns at the bottom of the shell, and in the hollow
of the plug, the ports 3 and i being long enough and wide enough
to allow the air free circulation as shown by the arrows. The flame
must not be too large or it will fill the whole interior with gas and
prevent air getting in; the flame will then burn at the port i in the
air and will not enter the cock. Suppose it to be burning regu-
larly in the cock as shown in the drawing, then if the plug is suddenly
turned round so that port 3 closes upon the atmosphere port i,
and opens upon the cylinder port 2, the air supply will be sufficient
to keep the flame living till the mixture contained in 2 reaches it
The explosion then occurs. The port 2 is of the same shape as i,
so that the flame causes the gases to circulate the same as the air
did when open to it ; the mixture comes in contact with the flame
by circulating through the plug. If the port 2 is made so small
that no circulation occurs, then the ignition will be a very uncer-
tain matter ; as the gases will require to get at the flame by diffu-
208
The Gas Engine
sion, which is a slow process, and the flame may be extinguished
before they arrive at it. The explosion of course extinguishes the
flame, but when the plug is again rotated to open to the air, the
external flame relights it and it is ready for another ignition.
FIG. 73.— Barnett's Igniting Valve (flame).
Igniting Arrangements 209
Hugoris Igniting Valve. — In the small Hugon engine Barnett's
method was first applied in a fairly successful manner.
The valve is shown in section at fig. 74.
The sectional plan, fig. 74, shows the internal flame lit and
burning in the ignition port i ; the external flame 2 burns close to
it in this position, so as to be ready to light it when wanted. The
gas for the internal flame is supplied under higher pressure than
that of the ordinary gas mains by a bellows pump and small
reservoir through the flexible rubber pipe. For the external flame
the gas is used at the ordinary pressure.
When ignition is required, the valve moves rapidly forward
causing the port i to close to atmosphere first, and then to open
to the cylinder port 3, as shown at the other end of the slide.
The explosive mixture which fills the port 3 is at once
ignited and the flame finds its way from the port into the cylinder
itself ; the port is necessarily filled with pure explosive mixture
free from any admixture with exhaust gases, as all the mixture
before entering the cylinder must pass through it and so sweep
before it any burned gases into the cylinder. Hence the mixture
in the port will be more ignitable than that in the cylinder, as the
mixture there is diluted in part with exhaust gases while that in
the port is free from them.
The explosion is thus exceedingly certain and regular ; when
it occurs it extinguishes- the internal flame and at the same time its
superior pressure forces back the gas in the rubber pipe while the
port i remains open to the cylinder.
The return of the slide again opens it to the atmosphere, and here
is seen the necessity of using the gas under some pressure. Before it
can relight at the external flame, the products of combustion must be
expelled from the gas pipe ; if the gas were under only the ordinary
gas main pressure there would be no time for this, and the valve
would return to ignite without a flame. The expedient of increas-
ing pressure is somewhat clumsy but it acts fairly well. The port i
is made large to give space for the air necessary to support the
flame while the ignition port is passing from atmosphere to
cylinder port. At the moment of explosion, the cylinder is com-
pletely closed from the air.
p
2IO
The Gas Engine
The explosion is therefore completely contained within the
cylinder and no sound is heard.
Igniting A rrangements 2 1 1
In the engine at the Patent Office Museum Mr. S. Ford con-
siderably improved the igniting arrangement by intercepting the
rush back to the gas pipe by a light check valve ; he was thus able
to use gas under the ordinary gas main's pressure and dispense
entirely with Hugon's gas pump and reservoir. The explosion, in-
stead of forcing a considerable volume of burned gases down the
gas pipe, simply closed the check valve, which opened as soon as
the igniting port reached the air again, and so gave the gas stream
at once.
Otto's Igniting Valve. — The igniting valve used in the Otto
and Langen engines is a further development of Barnett and
Hugon's igniting devices.
As applied to the compression engine there is one alteration,
very slight, but very essential.
In the Lenoir and Hugon engines, as well as the Otto and
Langen, the pressure in the cylinder is the same, or in some cases
less than that of the external atmosphere, that is, before ignition.
It is therefore an easier matter to transfer a flame burning quietly
in the air to the cylinder without danger of extinction. When the
gases to which the flame is to be transferred exist at a pressure
some 40 to 50 Ibs. per square inch superior to that of the flame
itself, it is not so easily seen how the flame is to be transferred
without extinction. Generally described the arrangement is as
follows. A small quantity of coal gas is introduced into the
upper part of a cavity in the ignition slide ; being lighter than air it
remains separate from it and has no tendency to mix with the air
beneath it, except by the slow process of gaseous diffusion. At the
surface of contact with the air, it is ignited and burns with a blue
flickering flame. The movement of the slide cuts off communica-
tion with the outer atmosphere, and very shortly thereafter opens
on the admission port of the engine, but before doing this it opens
on a small hole communicating with the cylinder. This hole com-
municates with the gas passage in the upper part of the slide, so
that the gases under pressure enter and force the gas downwards,
the pressure rising in the port more slowly than would occur if
the main port opened at once. The pressure is therefore nearly
level with that in the cylinder when the main port opens, and the
flame still burning at the point or surface of junction between the
P2
212
The Gas Engine
gas and air, ignites the mixture. If the pressure was not raised
in the igniting port by pressing the gas downwards and thereby
avoiding a rush past the flame portion, the rush would often
extinguish the flame and an ignition would be missed. The
apparent difficulty of transferring the flame from atmosphere to
FIG. 75. — Section, Otto Igniting Valve.
40 Ibs. above it is thus simply and beautifully overcome. By using
a portion of gas in the upper part of the valve cavity, the difficulty
of the blow back of explosion down the gas supply pipe is also
overcome, as the gas supply can be cut off before the explosion or
Igniting A rrangements 2 1 3
compression pressure comes on. It is cut off just before the valve
closes the flame port to atmosphere.
Fig. 75 is a vertical section showing the flame cavity in the slide,
in the act of introducing coal gas at the upper part and inflaming
it at the point of junction, between gas and air.
The slide A contains a forked passage B communicating at the
lower passage with the air inlet c, and at the upper passage with
the funnel F, which are both in the valve cover D, which holds the
valve against the engine face. The jet c has a flame constantly
burning into the funnel, which becomes heated, with the effect of
drawing a current of air through the forked passage when its ports
are in proper position ; the direction of the current is shown by
the arrows. The pipe j supplies coal gas which passes along the
gutter i, cut in the cover and valve faces, into the forked passage
c, and thence to the funnel F where it is inflamed and burns as
shown. When the movement of the slide cuts off communication
with the atmosphere, it also closes the gutter i and terminates the
supply of coal gas from the pipe j, but the upper part of the forked
passage contains gas ; a flame therefore flickers as shown. Just
before B opens on the port L, fig. 76, the hole K, fig. 75, opens and
the pressure from the explosion space causes a flow into B, forcing
before it the gas contained in the hole, thereby intensifying the
flame by making the gas pass more into the air and bringing about
the equilibrium of the pressures. When B opens on L, the flame
is a vigorous one, and at once fires the whole charge in the explo-
sion chamber. Fig. 76 shows the slide with the port B at the
moment of opening on L. Fig. 77 is an end elevation of the
valve and cover, showing the ports and gutters dotted and lettered,
position same as in fig. 76. The method is carried out completely
and is a very perfect one indeed ; it is somewhat slow in action,
depending as it does on a proper ventilation of the forked passage
and the complete replacement of the burned products by fresh air
before the gas can burn properly in the cavity. If the engine be
run more rapidly than the draught of the funnel can clear out the
passage from the burned gases, then the flame cannot be lit in it
and an ignition will be missed.
It is a method exceedingly successful when ignition is not
required too frequently, but very troublesome and. uncertain for
2I4
The Gas Engine.
rapid ignition. The Otto and Langen engine only made 30 igni-
tions per minute, and the Otto compression engine makes but 80
FIG. 76.— Sectional Plan, Otto Igniting Valve.
Igniting Arrangements
215
ignitions per minute at full power ; its efficiency is good at these
rates, but at 150 per minute it is too slow in action.
Clerk's Igniting Valve. — The method of igniting the charge used
by Clerk is quite different from the other flame methods already
described ; the difference is necessitated by the greater rapidity of
ignition in engines with an impulse for every revolution.
To ventilate the igniting port in the Otto and Hugon slides
requires time, which cannot be given when the frequency of the
ignition approaches 150 to 200 per minute.
2i6 The Gas Engine
To meet this difficulty the author has invented several methods
both flame and incandescence, but the one to be described is
that at present in use in his engines ; it is very reliable and rapid,
as many as 300 ignitions per minute having been made with it
experimentally, or at the rate of 5 ignitions per second.
A portion of the explosive charge is allowed to pass from the
motor cylinder through a regulated passage to a grating placed at
the end of a cavity in the slide, and is there ignited by a Bunsen
flame ; the grating prevents the passage back of the flame, and
the mixture burns in the cavity without requiring the presence of
the external atmosphere. At each end of the cavity there is a
port opening to opposite sides of the valve, the one for lighting
the gases streaming from the grating, the other for communicating
with the interior of the cylinder at the proper time. The com-
munication with the cylinder is not made until the outer port cuts
off from atmosphere, and the flow of the gases is so regulated that
while this is being done, the flame still continues to be fed by
fresh supplies. It is evident that if too great a current be sent in,
the pressure will soon become equal to that in the cylinder, and
then the flow towards the cavity will cease and the flame become
extinguished j this is guarded against by proper proportioning of
the flow by the check pin. The pressure in the cavity when its
port opens on the cylinder port is still slightly less than that in the
cylinder, and the gases from the cylinder enter and are ignited.
By using gas and air already mixed in proper proportion, the ne-
cessity of ventilating is removed, and it is made possible to ignite
at the rate required by the system of impulse at every revolution.
Without this it would be almost impossible to get a passage cleared
out in time to allow of so frequent ignition, by a coal gas flame
burning simply in air. It was first used by Clerk in an engine work-
ing in February 1878, and has subsequently been used by Wittig
and Hees and by Robinson in the Tangye engine. In the form
here described it was first used by Clerk in November 1880.
Fig. 78 is a sectional plan of the igniting slide and cover as
well as the passage into the combustion space. The valve i con-
tains the cavity 2, furnished at the ends with the ports 3 and 4 ; at
the end 3 is placed the grating 5, communicating behind with
the explosion port 6, by a small hole 7 and a gutter in the
Igniting Arrangements
217
valve face, showing at fig. 78. A long pin 8 screwed into
the end of the slide controls the gases entering the space behind
the grating, and if need be can cut off communication altogether.
When the valve is in the position shown in the drawing, the mix-
Valve in position of flame lighting at external flame.
FlG. 78.— Sectional Plan, Clerk Igniting Valve.
ture is beginning to flow through the grating into the space 2,
and is ignited by the Bunsen flame 9 lying up against the valve
face. The Bunsen flame lies so close to the grating that im-
mediately inflammable mixture comes, it is lighted before it can
218
The Gas Engine
get time to fill the cavity ; if allowed to accumulate in the cavity
before lighting, a slight explosion ensues and a disagreeable report
is produced. The flame at the grating burns in the cavity, dis-
charging into the passage 10, and from thence to the atmo-
sphere. The movement of the slide cuts off communication with
the atmosphere, first on the Bunsen flame side, and then on the
Internal flame exploding mixture.
FlG. 79.— Sectional Plan, Clerk Igniting Valve.
inside of the valve ; very shortly after, the port 4 opens on the port
6 leading to the cylinder, and the gases then taking fire communi-
cate the flame to the whole contents of the compression space.
In fig. 79 the flame port in the valve is full open on the explosion
port of the engine. The slide then moves past the port and back
Igniting Arrangements
219
to the first position, where the operations described are repeated
and igniting again occurs.
This arrangement is very rapid in action, and . is capable of
igniting with the utmost regularity at a rate so high as 300 times
per minute, which is far in excess of the requirements of the
engine. Fig. 80 shows the Bunsen flame burning against the face
of the valve, ready to ignite the gaseous mixture.
"JBUNSEN BURNER
FIG. 80. — End Elevation, Clerk Igniting Valve.
Brayton's Flame Ignition.— The Brayton method of ignition
has already been described shortly in the description of the engine*
It is so beautiful and instructive that it merits further discussion.
The action will be made clearer by describing a well-known
laboratory experiment (fig. 81).
A piece of wire gauze, #, held a few inches from the Bunsen
lamp, ^, the gas being turned on, will prevent the flame when lit
22O The Gas Engine
above it from passing back through the gauze to the burner. The
gauze may be moved through a considerable distance' from the
Bunsen tube -without extinguishing the flame. The mixture of gas
and air streaming from the Bunsen passes through the gauze, and,
although igniting above, the heat is so rapidly conducted away by
the gauze, that the flame cannot pass through its interstices back
to the lower side. If an explosive mixture be confined under say
30 Ibs. per square inch pressure in a vessel, and a pipe from it
(fig. 82) leads to a pair of perforated plates with gauze between
them, a, then the cock b being opened gently (the valve c being
previously open), the mixture will stream through the plates into
FIG. 81. — Bunsen Flame burning above Gauze.
the atmosphere, and, if ignited, will burn at a without passing
back. If the cock b is opened suddenly a greater rush of flame
will occur, diminishing again if it is partly closed.
So long as enough mixture passes to preserve alive the flame
at a, then any increased quantity passing from the reservoir will
be burned ; the little flame increasing or diminishing as the
opening of the stop-cock valve is increased or diminished.
The action of the ignition in the Brayton engine is exactly
similar. The pressure on the flame side of the grating is slightly
below that existing on the other side ; the stream of cold gases
Igniting A rrangements
221
entering the engine cylinder immediately becomes flame on the
grating, and so expands, the volume of flame being changed as
required by the valve action of the engine.
This method is most successfully carried out in the Brayton
engine. The lack of economy is not due to the ignition, but to
the use of it under unsuitable circumstances. Without doubt this
Plan of grating.
FIG. 82. — Brayton Grating and Valve.
system, in a better combination, will come largely into use in
future and larger gas engines. It is unsuited for cold cylinder
explosion engines, but admirably adapted for hot cylinder com-
bustion engines of the second type.
222
The Gas Engine
(3) INCANDESCENCE METHODS.
The ignition of explosive mixtures by contact with heated
metallic surfaces has often been proposed, first by the late Sir
C. W. Siemens, and after him by the American, Drake. Dr.
Siemens, in one of his gas engine patents, proposes to ignite the
FIG. 83. — Sectional Plan, Clerk Incandescent Platinum Igniting Valve.
mixture by passing it through an iron tube, which is heated to red-
ness by a flame outside of it.
Drake constructed an engine in which the ignition was effected
in a similar manner. The difficulty is found in the rapid oxidation
Igniting A rrangements 223
of the tube, and the consequent necessity for frequent renewal.
Frequent attempts have also been made to heat a portion of the
interior surface of the cylinder, so that at a suitable time the mix-
ture might be exposed to it and fired.
The first arrangement of incandescent ignition successfully
applied to a compression engine is the invention of the author,
and is described in his patent, No. 3045, 1878. It was used in. an
engine exhibited at the Royal Agricultural Society's Show, Kilburn,
in 1879 (July).
Clerk's Igniting Valve. — Fig. 83 is a sectional plan of this
valve in position. Fig. 84 is a separate view of the valve looking
upon the face, and fig. 85 is the. platinum cage, full size, taken out
of the valve.
FIG. 84. — Face of Valve with Platinum Cage.
FIG. 85. — Platinum Cage.
The platinum cage consists of a box of platinum plate, with
numerous platinum ribs running across it. They are secured by
rivets running completely through, small platinum washers serving
to keep the plates at equal distances. The valve receives this
cage in a cavity, and it is tightly packed in its place with asbestos
and slate packing, a covering plate screwed down upon it securing
the whole in position. To start the engine, the reservoir contain-
ing gas and air under pressure is opened ; the small tap, i, then
opened allows mixture to flow through the diaphragm 2 (made
like the Brayton grating), and the mixture is ignited at the
small door 3, which is then closed. The flame flows through the
224
The Gas Engine
platinum cage, heating up its plates to a white heat in a few
seconds. On opening the starting cock of the engine, it moves,
and brings the igniting port 4, on the cylinder port 5, at the same
time opening on the port 6, in the cover, leading into the cavity 7.
The mixture in the cylinder then rushes through the cage, becom-
ing ignited, and the explosion reaches the cylinder ; the cavity 7
is so proportioned that each igni-
tion sends a measured quantity
of flame through the cage into it ;
the heat of the explosion at every
turn therefore supplies heat to
the platinum. This added heat
is sufficient to keep it at a white
heat. So long as the engine is
supplied with gas it gets an ig-
nition at every revolution, and a
portion of that heat goes to the
platinum to make up for loss by
conduction. The heating flame
used in starting the engine is
dispensed with immediately on
starting, and the engine runs con-
tinuously without outside flame.
This method is exceedingly reli-
able and rapid, but is not suited
for the governing arrangements
of small engines.
Siemens' Tube Method.- -Fig. 86
is an arrangement of Siemens'
method, as used by Mr. Atkinson
in his ' Differential ' engine, ex-
hibited at the Inventions Exhibi-
tion. The wrought iron tube i is
heated by the Bunsen flame 2,
the non-conducting casing 3 pre-
venting loss of heat ; the piston at the proper time uncovers the
hole 4 into which the tube is screwed, and the mixture entering
under pressure becomes ignited. In other engines the tube is
FIG. 86.— Hot Tube Igniter.
Igniting A rrangements 225
caused to communicate with the cylinder by a valve. This modi-
fication is exceedingly simple and works well ; care must be taken
to avoid overheating, or the explosion may rupture the tube. It
is inexpensive and easily renewed when disabled by oxidation.
(4) METHODS DEPENDING ON CATALYTIC AND
CHEMICAL ACTION.
The well-known property of spongy platinum of causing the
spontaneous ignition of a stream of hydrogen or coal gas directed
on it in air, has been proposed as a means of ignition by Barnett
( 1838). In the arrangement he describes, the platinum is contained
in a little cup screwed into the cylinder cover, and the compression
of the mixture causes its ignition by contact.
Platinum, however, soon loses this property, and the action is
at best too slow for use.
All flame methods of course depend on chemical action, but
one proposal has been made, to use the property possessed by
phosphorated hydrogen of igniting spontaneously in contact with
air. The phosphoretted hydrogen is conducted in small quantity
into the mixture to be exploded at every revolution, and its com-
bustion causes ignition.
This proposal has never been carried out in practice.
Summary.— -To the author's knowledge no other systems
of ignition have been proposed ; the flame methods are best
suited for small gas engines and will probably continue in use.
Considerable improvements may still be effected in ignition valves,
and it is possible that external flames may be entirely done
away with in future engines. It is somewhat humiliating to the
inventor to watch a powerful gas engine at work, developing say
30 horses, and to know that he can at once change the whole
and make the engine powerless by blowing out the external flame.
A combination of flame and incandescence methods will doubt-
less overcome this difficulty, and make the gas engine act without
visible flame and without the danger of extinction from draught,
to which the present igniting flames are subject.
It is improbable that either the first or fourth methods will
again find favour, the electric methods give too much trouble and
are at best uncertain.
226 The Gas Engine.
CHAPTER IX.
ON SOME OTHER MECHANICAL DETAILS.
A GOOD working cycle and good igniting arrangements are the two
most important factors in the successful working of a gas engine,
but there are other matters whose importance is only secondary
to those. The governing gear, the oiling gear, and the starting
gear, are of the greatest importance.
These matters will now be described.
The Governing Gear. — In the earlier gas engines, including
Lenoir and Hugon, the governing was attempted precisely as is
done in the steam engine, the source of power being regulated
by throttling. A centrifugal governor acted upon a throttle valve
regulating the gas supply, diminishing it when the speed became
too great and increasing it when the speed fell.
This was a very bad and wasteful method, as the engineer will
at once recognise from his knowledge of the properties of explosive
mixtures.
The limits of change allowable in the proportions of gaseous
explosive mixtures are very narrow, the gas present ranging from
T to TF °f tne total volume. A mixture containing \ of its volume
of coal gas in air has just sufficient oxygen to burn it and no
more ; any further increase of gas will pass away unburned, there
being insufficient oxygen present for its combustion.
This is therefore the richest mixture which can be used with
any economy.
A mixture of air and gas containing -^ of its volume of gas is
in the critical pr6portion ; any further dilution, however slight, will
cause it to lose inflammability altogether. The governor may
act in changing the proportion of gas and air between those limits,
that is, the explosion may be so reduced by dilution that it gives
On some other Mechanical Details
227
only naif the power per impulse obtainable with the strongest
mixture.
Any further dilution causes the engine to miss ignition al-
together, and discharge the gas it has taken into the exhaust pipe,
without obtaining any power from it. If, therefore, the governor
acts by throttling, the valve is only closed enough to cause the
mixture to be so weak as to miss fire ; as soon as that point is
reached the valve will be closed no further, because at that point
the speed of the engine will cease to increase. Fig. 7, p. 14, shows
the governor in action upon a Lenoir engine.
FIG. 87. — Section showing Otto and Langen Governor.
In modern compression engines the great loss of gas occasioned
by throttling is avoided by never diluting the mixture. Instead of
keeping up the same frequency of impulses but of less power, as
done in the steam engine, the gas is either full on or full off,
that is, the governing is effected by diminishing the frequency of
the impulses instead of diminishing their power.
In the specification of the Otto engine, 1876 (2081) the
governing is described as being effected by reducing the power
of the explosion. This is more impracticable in the Otto engine
Q2
228
The Gas Engine
than in the Lenoir, because, owing to the dilution of the charge by
the exhaust gases or air, the range of change in mixture is smaller.
The strongest mixture does not exceed i of coal gas in 8 of other
gases.
Governing — Otto and Langen Engine. — In this engine, in its
latest and best form, the governing is effected by missing impulses.
When the engine has received an impulse, the increase in speed
causes the governor to move a lever which disengages a pawl from
a ratchet, and so prevents the piston being raised and the charge
drawn into the cylinder. When the speed has fallen sufficiently
FIG. 88. — Otto and Langen Governor, showing Pawl and Ratchet.
the lever liberates the pawl, and the piston is then raised, taking
in the charge and exploding it. Fig. 87 is a sectional elevation of
the governing arrangements. The auxiliary shaft i is driven from
the main shaft 2 by the clutch 3, but the crank 4 and shaft i re-
ceive motion from 2 only by means of the pawl 5 falling into the
ratchet 3 ; so long as the governor lever 7 remains in the position
shown, the pawl is kept from engaging and the piston and valve
remain at rest ; so soon as the governor lever 7 liberates
the pawl, then it falls into the ratchet wheel by a spring and the
On some other Mechanical Details 229
auxiliary shaft receives one turn ; the crank 4, connected to the
lever 8 (fig. 88), lifts the rack, and the piston takes in its charge ;
.at the same time the valve opens to gas and air, then, when
the piston is full up, brings on the igniting flame. The ex-
plosion occurs and shoots up the piston, which on its down stroke
accelerates the motion of the power shaft, and if the limit of speed
is exceeded, the governor lever again interposes and prevents the
•charge and explosion till the speed falls.
When running without any load, the two horse engine tested
at Manchester by Clerk required only 6 ignitions per minute, con-
suming, including side lights, about 25 cubic feet per hour. The
shaft therefore ran as many as 15 revolutions merely by the power
stored in the fly-wheels.
The governing is effective but irregular.
Governing — Otto Engine. — The speed of the Otto compression
engine is governed by diminishing the number of impulses given
to the crank ; whenever the normal rate is exceeded, the governor
so acts that the gas supply is completely cut off for one or more
strokes of the engine, no impulse being given till it falls again.
One arrangement very commonly in use is shown at fig. 89.
The cam i upon the auxiliary shaft 2 is arranged to strike the
wheel 3 upon the lever 4, opening the gas valve 5 at the begin-
ning of the stroke and keeping it open till the end of the stroke
of the piston ; the gas passes from the gas valve by a passage to the
holes in the slide, when it streams into the air current entering the
engine by the admission port. Whenever the speed becomes high
enough, the governor 6 by the lever 7 shifts the position of the cam
i upon its shaft, so that the wheel 3 does not strike it; the gas valve
5 therefore remains shut for that stroke, and the piston draws air
alone into the cylinder. When the piston returns and compresses
the charge, the igniting flame enters as usual, but there being
no explosive mixture there, the piston moves out again without
impulse, expanding and discharging, charging and compressing an
uninflammable charge, till the reduction of speed calls again for an
impulse; the first ignition after the engine has made several re-
volutions without gas is always more powerful than the normal
one, because no exhaust gases being there the charge mixes in the
space with pure air and is not heated previous to explosion.
230
The Gas Engine
The arrangement in different Otto engines varies from this, but
the principle is always the same.
Fig. 90 is a recent and very clever governing arrangement as-
used in the smaller Otto engines.
FlG. 89. — Otto Governor and Connecting Gear.
The ordinary governor is entirely dispensed with, and the valve
itself carries a pendulum which governs.
The pendulum i, hanging from the pin 2 in the slide valve 3,
carries the long steel blade 4, which usually strikes the stem 5, and
opens the gas valve at the same time as the slide opens to the air.
Whenever the speed is exceeded, however, the motion of the valve
On some other Mechanical Details 231
in the direction of the arrow, exceeding a certain rate, the pendu-
lum i is left behind and depresses the steel blade 4, which therefore
misses the gas valve stem and for that revolution no gas enters.
So long as the speed is sufficient to swing back the pendulum no
gas enters ; as soon as it is insufficient to cause the pendulum to
leave its resting position against the valve, then gas is admitted.
As the pressure of the edge of the steel plate upon the valve
stem is in direct line with the centre of the pin upon which the
pendulum hangs, there is no tendency to move it, that is, the
governor does not furnish the power to open the gas valve. In
all the Otto governing arrangements this principle is adhered to ; the
Fin. 90. — Otto Pendulum Governor.
governor never furnishes the power to move the gas valve, but
only signals to the engine the proper time to give the motion,
the motion being always taken from the engine itself.
In electric light engines, which must give the impulse for every
two revolutions with some change of power, the gear is modified ;
instead of complete cut-off as first described, the cam upon the
shaft is made in several steps, so that the wheel upon the gas lever
is shifted from one to another as shown in fig. 91, where i is the
gas cam, and 2 is the wheel upon the gas lever. Those steps are
made to diminish supply of gas as much as possible without miss-
ing ignition, so that within narrow limits of changing load, the
232
The Gas Engine
engine may retain its frequency of impulse. Whenever this
range of permissible variation is exceeded, the wheel slips entirely
off the cam, and the engine then governs in the ordinary manner.
FIG. 91.— Otto Electric Light Governor.
Governing — Brayton and Simon. — In the Brayton gas engine
the governing was effected precisely as in the best steam engines,
by varying the point of cut-off. The entering flame was cut off,
sooner or later, as determined by the governor of the engine ; and
the admission of gas and air to the pump was simultaneously
regulated, the amount entering being diminished to keep the
pressure in the reservoir constant. The diagram, fig. 45, p. 158,
shows that the variable cut-off acted well.
Fig. 92 shows the governor of the petroleum engine.
The cam i, which opens the admission air valve on the motor
cylinder, is made tapering, so that the point of cut-off becomes
earlier and earlier as it slides in the direction of the arrow.
The supply of air was thus diminished. In this engine the
supply of petroleum could only be diminished by hand, two screws
on the oil pump, when screwed upwards, altering the connecting
On some other Mechanical Details 233
rod between the plunger and the eccentric, giving more or less
free movement, and thereby diminishing the throw of the pump.
The air supply to the engine was not diminished, so that the
pressure in the reservoir increased, and was blown off at a safety
valve placed upon the engine. This was a wasteful method.
The regularity of this engine in running was very great, being
far superior to any of the modern compression engines. It was,
however, not at all economical.
Simon's engine presented no new feature in its governing
arrangements. They were quite similar to Brayton.
FIG. 92. — Brayton Governor.
Governing — Clerk Engine. — The governing gear now used
upon this engine is the design of Mr. G. H. Garrett, Messrs.
L. Sterne & Co.'s works' manager. It is shown at figs. 93 and 94.
It consists of a gridiron slide placed between the upper and
lower lift valves. So long as the engine is at full power, the slide
i, fig. 93, is moved by the lever 2, fig. 94, from the ignition slide
of the engine already described, and remains open during the
forward stroke of the displacer piston.
The charge of gas and air therefore enters during the whole
stroke, and is sent into the motor cylinder to be compressed and
ignited at the proper moment. If, however, the load is lessened,
and the speed increases, and the governor 3 acts, it moves the
lever 4, which then catches the lever 2, and prevents the spring 5
from taking the slide i back and opening it. The displacer then
discharges its contents into the motor cylinder, but on its next
-out-stroke, the valve i being closed, it gets no charge but the
234
The Gas Engine
FIG. 93. — Sections and Plan, Governor Slide, Clerk Engine^
FIG. 94.— Clerk Engine showing Garrett Governor Gear,
On some other Mechanical Details
235
piston moves out, forming a partial vacuum behind it. The motor
cylinder, therefore, receives no charge from the displacer cylinder,
and the motor piston compresses and expands alternately the
burned gases behind it, while the displacer piston moves out and
in, expanding and compressing likewise. This goes on till the
governor signals reduction of speed, and disengages the lever 2,
by pushing down the lever 4, so that the spring 5 opens the slide
i, and the engine gets a charge.
This method works very well and economically ; it is necessi-
tated by the clearance space unavoidable in the Clerk engine
between the motor and displacer cylinders. If gas were cut off as
in the Otto, that space filled with mixture would be lost every time
the governor acted.
Governing — Tangye Engine. — Messrs. Tangye's gas engine is
now controlled by a very ingenious governor, the invention of
FIG. 95. — Governing— Tangye Engine.
i i, moved
Mr. C. W. Pinkney. It is shown at fig 95. The rod
to and fro by an eccentric, carries with it the bracket 2, into
which is fixed the pin 3 ; on this pin the lever 4 is swung, and
moves to and fro with the bracket ; the lever is pressed gently
downwards by the spring 5, and the lower part of the lever is
formed into an incline at 6, so that as it moves the spring presses
it against the roller 7. So long as the engine does not exceed its
proper speed, the lever 4 does not rise above the position shown
236 The Gas Engine
in the figure when it is moving in the direction of the arrow, and
accordingly its knife edge end strikes the lever 8 and, acting
through the intermediate links, opens the gas valve 9, The
engine gets its charge of gas every time the gas valve opens. If
the speed becomes too great, then the upward velocity given to
the lever 4 by the stationary roller 7 forcing against the incline is
such that the knife edge lever 4 rises above the end of the lever
8, and the gas valve remains closed. When the speed falls
sufficiently the lever 4 again strikes the lever 8 and opens the gas
valve.
The incline governor works well and is exceedingly sensitive
to change in speed : by altering the compression upon the spring
5 the speed of the engine can be varied.
Oiling Gear. — In the steam engine the comparatively low
temperature of the steam within the working cylinder and the
fact of its condensation upon the walls and piston renders the
task of lubricating an easy one. The lubrication need not be
absolutely continuous and the nature of the oil may vary much
and no harm is done.
With the gas engine, the intense flame filling the cylinder at
every stroke quickly destroys the film of oil with which it is
covered, and necessitates its continuous renewal.
If animal oil be used, its decomposition leaves considerable
charred matter, which speedily coats the piston and cylinder,
causing friction and danger of cutting. A good hydrocarbon, on
the other hand, even when subjected to intense heat, decomposes
into gases without leaving any appreciable amount of carbon :
mineral oils should therefore alone be used for the cylinder and
ignition slide.
The amount of oil required for these parts is small per day,
but it must be regularly applied ; the burned film removed from
the surface of the cylinder at every explosion must be regularly
replaced or abrasion of the surfaces would speedily ensue.
In the Otto engine the oil required is supplied during the whole
action of the engine ; it commences with the movement of the en-
gine, continues so long as it is running, and stops when motion ceases.
Fig. 96 shows the Otto oiling cup, one of which is placed, as
shown in the drawing, fig. 97, at the middle of the cylinder to
On some other Mechanical Details
237
lubricate the piston and slide ; the pipes 4 and 5 lead to the
piston and slide.
The pulley i is driven slowly from the auxiliary shaft by a
strap, and as it rotates it carries the wire 2 round on the pin 3,
FIG. 96. — Illustration of action of Otto Oiler.
fig. 96, alternately dipping into the oil and wiping it off to the
pin, from whence it drops into the trough 4 and runs by a hole
into the tubes. The amount of oil so discharged can be regulated
by the diameter of the wire. The oil flows along the pipes 4 and
FIG. 97. — Arrangement of Otto Oiler.
5, fig. 97, and drops into holes at 6 and 7, the one oiling the piston
every time the trunk comes forward, the other oiling the valve by
suitable gutters.
The Clerk oiling cup is shown at fig. 98 ; it is not automatic.
The screw pin i is set in a position marked for each cup, the
233
The Gas Engine
motor cylinder cup giving 15 drops per minute, and the valve cup
5 drops per minute.
In both Otto and Clerk engines the slide valves should be
taken out and cleaned once a week. The charred oil should be
carefully scraped out of the gas gutters and igniting ports ; the
piston also should be drawn occasionally, once in three months
being sufficient. The interior of the cylinder should then be.
cleaned, especially the explosion space. The Otto exhaust valve
should be taken out every week and cleaned. The Clerk upper
FIG. 98. - Clerk Oil Cup.
.and lower lift valves require cleaning once every month if the
engine is hard worked.
In working gas engines the two points requiring attention are
oiling and cleaning. Never run the engine, without oil, and clean
regularly. Never start without seeing that the water circulation
is open.
Starting Gear. — Till very lately, gas engines of every power
were started by manual labour ; in small machines the inconveni-
ence is not great, but with large engines such as those giving
from 20 to 50 indicated horses when at full power, the friction
is so considerable that difficulties arise. It is difficult to reduce
friction so much that a large machine may be turned with suffi-
cient velocity by a couple of men, to get a sure and easy start.
The Brayton petroleum engine was the first to use reservoirs
On some other Mechanical Details
239
for retaining sufficient air for starting, but they were so faultily
constructed, that leakage and loss were so frequent that the appa-
ratus was of little use. Many arrangements have been described
by inventors, but no starting gear found its way into public use
till that invented by the present author in the end of 1883. The
Clerk engine was the first to use starting gear in public, at the
FIG. 99. — Clerk Starting Gear.
beginning of 1884. Since then over 100 engines have been fitted
and are at daily work with it.
The Otto engine speedily followed Clerk's in the application
of gear, and after them came Tangye and Atkinson.
Starting Gear — Clerk Engine. — The starting gear used in the
Clerk engine is shown at figs. 99 and 100. Its action is as follows.
240
The Gas Engine
The flap, valve i, in the communicating pipe between the displacer
and motor cylinders is closed, while the engine is running, by the
handle 2 ; the gases in the displacer are thus prevented from
entering the motor cylinder, and are compressed through the
valve 3, which is an automatic lift, into the reservoir 4, by the stop-
valve 5, which must of course be open.
The ignition being stopped, the speed of the engine falls, and
the flap is opened for a few strokes, to allow the speed to get up
again. It is then closed again, this being repeated till the reservoir
4 is charged with a mixture of gas and air at 60 Ibs. per sq. in.
above atmosphere. Five minutes gives ample time to charge
FIG. loo.— Clerk Starting Valve.
from completely empty to 60 Ibs. Three minutes suffice if the
charge has not been completely taken from the reservoir during
the previous start. The relief valve at 6 prevents charging above
60 Ibs. per sq. in., the excess blowing into the exhaust pipe<
When the reservoir is charged the stop valve 5 is screwed down
and the charge is retained in the reservoir till wanted. The
reservoir is made of steel, the sides being \ in. thick and the ends
f '; it is welded throughout, and is tested before leaving the works
at 1000 Ibs. per sq. in.
The screw down valve 5 and the joint where it is screwed
On some other Mechanical Details
241
into the end form the only joints for loss by leakage ; numerous
joints must be avoided, as it is often necessary to leave the
reservoir charged for weeks ; the faintest leakage would in so long
a time lose the contents, and so the start would require to be
made by hand.
The reservoir is so pressure tight, when made as described,
FIG. 101. — Otto Starting Gear.
that the author has left one standing for six weeks and started the
engine with ease with what remained.
The starting is effected as follows :
The engine is placed in such position that the motor crank is
on the full in centre. The displacer is therefore half forward, the
reservoir stop valve is opened, the Bunsen burner is lit, and the
gas cock of the engine set at the starting mark. The starting
handle 7 is then moved in, opening the valve 3, fig. TOO, the gases
R
242 The Gas Engine
entering press forward the displacer piston and fill the compres-
sion space of the engine, pressing forward the motor piston when
its crank comes off the centre. The starting handle is then let
go, and the motor piston runs over its ports discharging the con-
tents both of motor and displacer to atmosphere. The engine has
thus received a double impulse, one in each cylinder ; it is enough
to bring round the piston, compress the mixture and get an igni-
tion. One opening or at most two openings of the starting valve are
enough. The reservoir contains enough to give six successive starts.
After starting, the reservoir should be again charged and closed
so that it may be ready when required.
The gear works very well and is easily handled.
To those accustomed to see gas engines started by hand, it is
somewhat astonishing for the first time to watch a large machine
move away at once by a mere finger touch upon a valve.
Starting Gear — Otto Engine. — The starting gear used in the
Otto engine is shown at fig. 101. It consists of the reservoir i,
the charging and starting valve 2 and a stop valve. The charging
valve is loaded so that it does not open with a pressure less than
40 Ibs. per square inch, as it communicates with the compres-
sion space 4. It follows that the compression of the charge in the
cylinder does not lift it, but as soon as the gases explode, the
pressure lifts the valve, and the reservoir gets filled slowly with
burned gases. If the valve is left open long enough the pressure
will rise to within 40 Ibs. of the maximum explosion pressure, that
is, about no Ibs. per square inch above atmosphere. The stop
valve being screwed down, the gases are retained ready to start
the engine when wanted. To start, the stop valve at the reservoir
is opened, and the engine crank placed in such position that it is
off the centre and on its impulse stroke. The gases then pass
through the valve 2 into the cylinder 4, and the valve 2 closes at
the end of the stroke actuated by the cam 3. One impulse is
thus given and is repeated at the proper time by the action of the
cam 3 upon 2, through the intermediate lever. The pressure re-
quired is high, because only one forward movement of the piston
is available for every two revolutions of the engine. The twin
engine therefore starts more easily than the ordinary type of Otto.
This gear also works well ; it was patented before the Clerk gear,
but was later in being introduced into public use.
243
CHAPTER X.
THEORIES OF THE ACTION OF THE GASES IN THE MODERN
GAS ENGINE.
THE general principles developed in this work explaining the
causes of the economy of the modern gas engine were first enun-
ciated by the author in a paper read before the Institution of
Civil Engineers in April I882.1
He then classified gas engines in three great groups :
Type i. — Explosion, acting on piston connected to crank. (No
compression.)
Type 2. — Compression, with increase of volume after ignition,
but at constant pressure.
Type 3. — Compression, with increase in pressure after ignition,
but at constant volume. »
It was proved that under comparable conditions the relative
theoretic efficiencies of the three types were
Type i = 0*21
Type 2 = 0*36
Type 3 = 0-45
It was also shown that in the actual engines the real efficiency
could not be so high as the theoretic, mainly because of the large
proportion of heat lost through the sides of the cylinder, by the
exposure of the flame which filled the cylinder to the comparatively
cold enclosing walls. A balance sheet was given showing the
disposal of 100 heat units by a compression engine. Of the 100
heat units, 17*83 were converted into indicated work, 29*28 were
1 The Theory of the Gas Engine/ by Dugald Clerk : Minutes, Institute Civil
Engineers, London. Paper No. 1855. April 1882.
R 2
244 The Gas Engine
discharged with the exhaust gases, and 5 2 -89 units passed through
the sides of the cylinder into the water jacket.
The economy of the Otto engine over its predecessors, the
Lenoir and Hugon engines, was clearly proved to be due to the
fact of its using compression previous to explosion.
These conclusions were very generally accepted by scientific
and practical men who had studied the subject, and in February
1884 the late Prof. Fleeming Jenkin, then Professor of Engineering
at the University of Edinburgh, delivered a lecture at the Institu-
tion of Civil Engineers in London, on ' Gas and Caloric Engines.' l
He had recalculated the efficiencies due to compression, with the
result of corroborating the present writer's conclusions. He
states :
* If I were to compress gas to 40 Ibs., a pressure which is used
not unfrequently, the theoretical efficiency would be 45 per cent.
We actually get something like 24 or 23 per cent; we know that
one-half of the heat is taken away by external cooling. Thus we
find a very close coincidence between the calculated efficiency of
those engines and that which we actually obtain, only we throw
away about one-half of the heat in keeping the cylinder cool
enough to permit lubrication. If we compress to 80 Ibs. we have
a theoretical efficiency of 53 per cent If we do not compress at
.all, as Mr, Clerk has told you, we have a theoretical efficiency of
only 21 per cent, so that we have it in our power to increase the
theoretical efficiency very greatly by increasing the pressure of the '
gas and air before ignition. I have no doubt that the great gain
of efficiency in the Clerk and Otto engines is really due to the
fact of the compression ; this being done in a workmanlike way
and carried to a very considerable point.'
The advantages of compression could not be stated with more
clearness and truth.
In the same year there was published in Paris an able work
entitled ' Etudes sur les Moteurs a Gaz Tonnant,' by Professor Dr.
AimeWitz, of Lille, in which the theoretic efficiencies of the different
types of cycle are calculated for a maximum temperature of ex-
plosion of 1600° C, and temperature before explosion of 15° C.
1 ' Heat in its Mechanical Applications ' : Institute Civil Engineers Lectures.
Cession 1883-84.
Theories of Action of Gases in Modern Gas Engine 245
He adopts the same classification as the 'present writer did in
1882, and finds the efficiencies :
Type i = 0*28
Type 2 = 0*38
Type 3 = 0-44
which are almost identical with the author's figures.
He also arrives at the conclusion that compression is the great
source of economy in the modern gas engine. At p. 53 he says :
' I find myself again in agreement with Mr. Dugald Clerk when he
affirms that the success of Otto is due to compression alone, and
not to the extreme dilution of the explosive mixture in the pro-
ducts of the combustion of a precedent explosion.'
He then proceeds to quote from the present writer's paper, and
adheres to the statement that —
'Without compression previous to ignition an engine cannot
be produced giving power economically and with small bulk.'
Compression previous to ignition gives two great advantages :
(1) A thermodynamic advantage (improved theory of the
cycle) ;
(2) Higher available pressures and smaller cooling surfaces
—the joint result being an economy in practice nearly fourfold
that of the old non-compression engines.
MR. OTTO'S THEORY.
Previous to 1882 the nature of the improvement obtained by
compression was imperfectly understood, and this notwithstanding
the very clear, though qualitative, statements of Schmidt, Million,
and Beau de Rochas. An erroneous theory of the cause of the
economy of the Otto engine was widely circulated and gained
considerable support.
It was enunciated in Mr. Otto s specification of 1876, No. 2081,
and it was and is still, so far as the author is aware, supported by
men so distinguished as Sir Frederick Bramwell, Dr. Slaby of
Berlin, Prof. Dewar of the Royal Institution, and Mr. John
Imray.
246 The Gas Engine
According to Mr. Otto, all gas engines, previous to his patent
of 1876, obtained their power from the explosion of a homoge-
neous charge of gas and air. By the explosion excessive heat was
evolved, and the pressures produced rapidly fell away ; the exces-
sive heat was rapidly absorbed by the enclosing cold walls.
This caused great loss and gave very wasteful engines. Two
methods were open to obtain better economy :
ist, by using a very rapid expansion, so that the heat had but
little time to be dissipated ;
2nd, by using slow combustion ; that is, by causing the in-
flammable mixture to evolve its heat slowly, so that the production
of excessive temperatures and pressures was avoided.
By the first method all the heat was supposed to be evolved at
once, and a high temperature was produced : by the second
method the heat was evolved gradually so as to give a low temper-
ature and pressure which was sustained throughout the stroke,
and which was advantageously utilised by the piston while moving
at a moderate speed. Mr. Otto states that this gradual evolution
of heat may be produced by stratifying the charge of gas and air.
Instead of using the homogeneous charge of Lenoir and Hugon,
Mr. Otto uses a charge which he states is not homogeneous but
heterogeneous. He affirms that his invention lies in the method or
process of forming this stratified charge in a gas-engine cylinder,
and that, in addition to the explosive mixture, there must be present
in the cylinder a mass of inert gas which does not burn but which
serves to absorb the heat of the explosion and prevent the loss
which would otherwise occur by the cooling effect of the cylinder
walls.
The * inert ' gas may be either air alone which is capable of
supporting combustion, or the products of combustion which are
incapable of supporting combustion, or a mixture of both. It is
not sufficient that a mere film of this inert gas be present ; there
must be what is termed a * notable ' quantity.
Mr. Otto proposes to form this heterogeneous or stratified
charge by first drawing into the cylinder a charge of air alone ;
and second, a charge of explosive mixture, or by leaving in the
cylinder a sufficient quantity of the products of a previous com-
bustion to form a * notable ' quantity of inert diluent.
TJteories of Action of Gases in Modern Gas Engine 247
The compression space in the Otto engine is supposed to con-
tain a sufficient volume of burned gases to form the inert diluent,
so that the whole stroke of the piston is available for taking in the
explosive charge.
Suppose the piston to begin its charging stroke : the coal-gas
and air mixture flows into the cylinder through the inlet port and
mixes to some extent with the inert gas already in the space ; but
the mixing is incomplete, and at the piston itself the charge is
supposed to consist entirely of exhaust gases. So that, while
the charge at the igniting port is readily explosive, that at the
piston is not explosive at all, and between the igniting port and
the piston the composition of the charge varies from point to
point.
This ' arrangement of the gases ' is supposed to be retained
during compression, and exist at the moment of explosion. The
compression space contains a ' packed charge,' which consists of
an explosive mixture at the one end, and between the explosive
mixture and the piston a cushion of inert fluid, which is uninflam-
mable and serves the double purpose of relieving the piston from
the shock of explosion and absorbing heat which would otherwise
be lost by conduction.
By this device, heat is gradually evolved. The flame originated
in the port burns at first with great energy and spreads from one
combustible particle to another, more and more slowly as it ap-
proaches the piston, where the particles are dispersed more and
more in the inert gas. The mixture is so arranged that this burn-
ing lasts throughout the whole stroke, and is complete very shortly
before the exhaust valve opens.
The entire cylinder is never completely filled with flame, but
the charge at one end has burned out before the flame arrives at
the other end.
Dr. Slaby comes forward in support of this hypothesis in an
interesting report published as an Appendix to Prof. Fleeming
Jenkins' lecture already referred to.
Dr. Slaby states : ' The essence of Otto's invention consists in
a definite arrangement of the explosive gaseous mixture, in con-
junction with inert gas, so as to suppress explosion (and neverthe-
less insure ignition).
248 The Gas Engine
' At the touch hole, where the igniting flame is applied, lies a
strong combustible mixture which ignites with certainty. The
flame of this strong charge enters the cylinder like a shot, and
during the advance of the piston it effects the combustion of the
farther layers of dispersed gaseous mixture, whilst the shock is
deadened by the cushion of inert gases interposed between the com-
bustible charge and the piston.
'The complete action takes place in a cycle of four piston
strokes. The first serves for drawing in the gases in their proper
arrangement and mixture ; the second compresses the charge ;
during the third the gases are ignited and expand ; and finally,
by the fourth the products of combustion are expelled. The
essential part of the working is performed by the first of these
strokes, by which the charge is drawn in and arranged, first air,
then dilute combustible mixture, and finally strong combustible
mixture. This arrangement is obtained by the working of the
admission ' slide. Moreover, after discharge of the products of
combustion, a portion remains in the clearance space of the
cylinder, and this constitutes the inert layer next the piston. By
this peculiar arrangement of the gases, the ignition and combus-
tion above described are rendered possible, whilst the products of
previous combustion form a cushion, saving the piston from the
shock of the explosion of the strongly combustible mixture at the
farther end of the cylinder.'
Having stated the essence of Otto's invention, Dr. Slaby pro-
ceeds to compare the Otto and Lenoir indicator diagrams, to show
that the Otto diagrams prove that the above actions occur in the
engine. He finds that the Otto expansion line is somewhat above
the adiabatic line, and that the Lenoir expansion line is below it.
That is, the Otto diagram gives evidence of heat being added or
combustion proceeding in the cylinder during the whole expansion
stroke, and the Lenoir diagram gives evidence of loss of heat, not
gain, during a similar period. If a mass of expanding gas traces
on the diagram the adiabatic line, then it appears as if no loss of
heat occurred ; but as the temperature of the flame filling the
cylinder is known to exceed 1200° C., it must be losing heat to
the water jacket. To make the expansion line keep up to the
adiabatic a great flow of heat into the gas must be taking place,
Theories of Action of Gases in Modern Gas Engine 249
and as the only source of heat is combustion, it follows that the
gas is burning during the expansion period.
Dr. Slaby calculates the proportion of heat evolved by the ex-
plosion in the Otto engine as 55 per cent., leaving 45 per cent, to
be evolved during expansion.
This he states is due to the portion of the charge which con-
tinues to burn after the explosion.
The curve differs from Lenoir's in this, that while in Lenoir's
engine all the heat is evolved at the moment of explosion, leaving
none to be evolved during expansion, in Otto's only a part is
evolved at first, and the reserved portion keeps up the temperature
during expansion.
He concludes from his experiments that the action of the
Otto engine is truly as Mr. Otto states in his specification —
explosion is suppressed and a slow evolution of heat is obtained,
and this slow evolution of heat is the result of the invention and
the cause of the economy of the engine.
In addition to this indirect proof, experiments have been made
at Deutz and elsewhere to show directly that stratification has a
real existence in the Otto engine.
An Otto engine was constructed, specially fitted with two igni
ting valves ; one valve was placed on the side of the cylinder at
the end of the explosion space next the piston, so that it could
ignite the gases at the piston ; the other valve was the usual one
at the end of the cylinder, igniting the gases in the admission
port.
Experiments were made to discover if the side valve would
fire the mixture at the piston ; it was found that it did so. Con-
secutive ignitions were obtained there.
Diagrams were taken for comparison, with the end and the
side valves in alternate action, care being taken to keep the charge
in the same proportions during the trials. It was found that
although the side valve ignited as regularly as the end valve, yet
the diagrams were different. Instead of the usual rapid ascending
explosion line, the explosion took place more slowly, and the
maximum pressure was not attained till late in the stroke.
The ignitions were slower from the side valve than from the
end valve. If an uninflammable cushion, such as Dr. Slaby so
250 The Gas Engine
clearly describes, existed at the piston, one would expect that the
side valve would fail entirely, but it ignited quite regularly although
more slowly than the end valve.
This experiment is considered to prove stratification.
To make stratification visible to the eye, a small glass model
was constructed. It consisted of a glass cylinder of about \\ ins.
internal diameter, containing a tightly packed piston connected to
a crank ; the stroke was about 6 ins. ; when full back, the piston
left a considerable space to represent the explosion space. A
brass cover was fitted to the end of the tube, and in it was bored
a hole of about f in. diameter, representing the admission port ;
in this hole was screwed a pet cock to which a cigarette was
affixed.
On lighting the cigarette and then moving the piston forward
by the crank, it was seen that the smoke of the cigarette which
passed in did not completely fill the cylinder ; the smoke slowly
oozed in and left a large clear space between it and the piston.
The smoke was supposed to represent the charge of gas and air
rushing in, and the clear air behind the piston the cushion which
was said to exist in the Otto engine. It was supposed that in the
glass cylinder was repeated on a small scale the action of the gases
occurring on a larger scale in the Otto engine. In a recent paper
in a German engineering journal, Dr. Slaby recounts this experi-
ment, and lays great weight upon it. He considers that it un-
doubtedly proves the truth of the Otto theory.
In discussion Mr. John Imray concisely states the Otto
position as follows :
'The change which Mr. Otto had introduced, and which
rendered the engine a success was this : that instead of burning
in the cylinder an explosive mixture of gas and air, he burned it
in company with, and arranged in a certain way in respect of, a
large volume of incombustible gas which was heated by it, and
which diminished the speed of combustion.'
And Mr. Bousfield states it in similar terms :
'In the Otto gas engine the charge, varied from a charge
which was an explosive mixture at the point of ignition to a charge
which was merely an inert fluid near the piston. When ignition
took place, there was an explosion close to the point of ignition
Theories of Action of Gases in Modern Gas Engine 251
that was gradually communicated throughout the mass of the
cylinder. As the ignition got further away from the primary point
of ignition, the rate of transmission became slower, and if the
engine were not worked too fast the ignition should gradually
catch up the piston during its travel, all the combustible gas being
thus consumed. When the engine was worked properly the rate
of ignition and the speed of the engine ought to be so timed that
the whole of the gaseous contents of the cylinder should have
been burned out and have done their work some little time before
the exhaust took place, so that their full effect could be seen in
the working of the engine. This was the theory of the Otto engine.'
From these quotations it will be seen that Mr. Otto's supporters
agree that Mr. Otto has invented a means of suppressing explosion,
and substituting for explosion a regulated combustion, and that
•this process is the cause of the economy of the engine. They
are agreed that he has succeeded in preventing explosion, and
that he does this by arranging or stratifying the charge which is
to be used. They consider that engines previous to Mr. Otto's
were wasteful because they used a homogeneous and therefore
explosive charge, and that Mr. Otto's engine is economical be-
cause it uses a heterogeneous or stratified charge, which is con-
sequently non-explosive.
Discussion of Mr. Otto's Theory.
The primary fallacy of Mr. Otto's theory lies in the assumption
that previous engines were more explosive than his, and that in
previous engines all the heat was evolved at once : as a plain
matter of fact this is incorrect. In the Lenoir and Hugon engines,
as in all explosive engines, little more than one-half of the total
heat is evolved by the explosion, and the portion reserved is evolved
during the stroke of the engine.
The following test of a Lenoir engine, made by the author in
London, very clearly shows the suppression of heat at first :
Lenoir engine rated at one horse power.
Cylinder 7^ inches diameter ; stroke uf inches.
Average revolutions during test, 85 per minute.
Gas consumed in one hour, 86 cubic feet.
252 The Gas Engine
With full load, indicated horse power, 1*17 (average of 9
diagrams).
Gas consumed per indicated horse power per hour, 73-5 cubic
feet.
Maximum temperatures of explosion, 1100° to 1200° C.
Mixture in engine i vol. coal gas, 12-5 vols. of air and other
gases. «
Heat evolved by explosion, 60 per cent, of total heat.
The proportion of the mixture was calculated from the points of
cut-off on the diagram, and after making allowance for the volume
of burned gases in the clearances of the engine. It will be
observed that only 60 per cent, of the gas is burned at first, leaving
40 per cent, to be burned during the stroke, and also that the
temperature of the explosion never exceeds 1200° C. Now in the
Otto engine, according to Thurston, 60 per cent, of the heat is
evolved at explosion, and 40 afterwards, and the usual maximum
temperature is about 1600° C. So that, so far as the slowness of
the explosion is concerned, there is no difference, and in the in-
tensity of the temperature produced, the Otto exceeds the Lenoir.
It is difficult to understand how Dr. Slaby could fall into so-
obvious an error as he did, and suppose that more heat was kept
back in the case of the Otto explosion. At the time he wrote his
report, accounts of Hirn's, Bunsen's, and Mallard's experiments
on explosion were in existence, all of them agreeing on the fact
of a large suppression of heat at the maximum temperature of the
explosion, although differing in the explanation of the fact.
Him even stated that in the Lenoir engine the pressures fell
far short of what should be, if all tne heat were evolved at once.
Yet Dr. Slaby, in the presence of all this definite and carefully
ascertained knowledge, is astonished when he finds only 55 per
cent, of the total heat evolved by the explosion in the Otto engine,
and the only explanation which occurs to him is that of stratifica-
tion.
If stratification exists at all in the engine, then it produces no
measurable change in the explosion ; it neither retards the evolu-
tion of heat, nor does it moderate the temperature.
The explosion and expansion curves are precisely what they
would have been with a homogeneous charge.
Theories of Action of Gases in Modern Gas Engine 253
The mere fact that heat is suppressed in the Otto explosion
proves nothing, because a precisely equivalent amount of heat is
suppressed in all gaseous explosions, and Dr. Slaby's contention,
based upon the supposed peculiarity of the Otto, falls to the
ground.
Dr. Slaby has been led into error by the fact that the expansion
line of the Lenoir diagram falls below the adiabatic, while the
expansion line of the Otto diagram remains slightly above it or
upon it. He assumes that in the Lenoir no heat is being added
during expansion, whereas just as much heat is being added, or
just as much combustion is proceeding during the Lenoir stroke,
only the cooling of the cylinder walls is greater, and the heat is
abstracted so rapidly that the line falls below the adiabatic. This
is due to two causes, (i) the greater proportional cooling surface
exposed by the Lenoir engine, and (2) a longer time of exposure.
The absence of compression and the slow piston speed makes the
loss greater.
Although quite as much heat is evolved during the stroke, it
is overpowered by the greater cooling, and the line falls under the
adiabatic. This fall is evidence of greater cooling, not of less
evolution of heat.
In a recent paper,1 * Die Verbrennung in der Gasmaschine,
Professor Schottler makes this explanation of the difference be-
tween the lines, and states that * Whether stratification exists or
does not exist in the Otto engine it is unnecessary, and is not the
cause of the slow falling of the expansion line.' In all crucial
points the Otto theory breaks down, as proved by diagrams taken
from his engine.
The explosion is not suppressed ; the maximum temperatures
produced are not lower than those previously used ; the mixture
used is not more diluted than in the previous engines, and the in-
tensity of the pressures, as well as the rate of their application, is
greater.
The mixture in the engine from Slaby's figures is i vol. coal
gas to 10-5 vols. of other gases, and from Thurston's figures i
vol. coal gas to 9-1 vols. of other gases, while Lenoir often used
i vol. gas to 12 of air.
1 Zeitschrift des Vereines deutscher Ingenieicre. Band xxx., Seite 209.
254 The Gas Engine
The engine instead of using a less explosive power than the
Lenoir engine uses one more intensely explosive.
The effect of the reduction of cooling surface and increase of
piston velocity is to diminish the loss of heat to the cylinder walls,
and the slowly descending line is not the cause of the economy,
but is the effect and evidence of it.
Stratification. — The inquiry into the existence or non-existence
of stratification in the cylinder has no practical bearing on the
question of economy, as the explosion curves act precisely as they
would with homogeneous mixtures. Scientifically, however, the
question is interesting and will be shortly considered.
The evidence which it is considered proves its existence in the
Otto engine is in the author's opinion most unsatisfactory. Dr.
Slaby distinctly asserts the existence of an inert stratum next the
piston, 'interposed between the combustible charge and the piston/
and Mr. Imray speaks of the 'arrangement of the charge in respect
of a large volume of incombustible gases,' and Mr. Bousfield of
'a charge which was merely an inert fluid next the piston.' Yet
all the evidence in support of these positive assertions is given by
one experiment made with an Otto engine, and one with a small
glass model. The evidence given by the experiment on the engine
itself, in the author's opinion, disproves stratification in the Otto-
sense altogether. If the inert stratum next to the piston had any
real existence, then the side igniting valve in the experiment made
by Mr. Otto, should not have ignited the mixture at all. The fact
that it did ignite regularly and consecutively, proved most dis-
tinctly that the gas next the piston was not inert but was explosive,
and being explosive in itself it could not act as a cushion to-
absorb heat or shock. That experiment alone settles the ques-
tion, and proves at once the visionary nature of the cushion of
inert gas next the piston.
The fact that the ignitions were slower than those from the end
slide does not get rid of the fact that ignition did take place, and
to those who understand the sensitive nature of any igniting valve,
it will not be difficult to comprehend how small a difference in
adjustment will cause late and slow ignitions. At the very utmost
the experiment points to a small difference in the dilution of the
explosive mixture at the piston and that at the end port.
Theories of Action of Gases in Modern Gas Engine 255
Experiments made by the author also prove that the mixture
in the Otto cylinder is present in explosive proportions close up to
the piston. The piston of a 3^ HP Otto engine was bored and
fitted with a screw plug, which carried a small spiral of platinum
wire in electrical connection with a battery ; the platinum spiral
projected from the inner surface of the piston by a quarter
of an inch. When the engine was running in the usual way, the
wire was made incandescent by the battery and the external light
was put out. It was proved that by a little care in getting the
platinum to a certain temperature, the engine worked as usual,
igniting regularly and consecutively. The spiral was made just
hot enough to ignite when compression was complete, but not hot
enough to ignite before compressing. If an incombustible stratum
had existed even so close to the piston as \ in. then the wire
should never have been able to ignite the charge at all. If the
wire was made too hot, then ignition often took place while the
charge was still entering, proving that no stratification existed even
while the charge was incomplete. A little consideration of the
arrangement of the Otto engine will show that stratification can-
not have any existence in it. The end of the combustion space is
usually flat, and sometimes the admission port projects slightly
into it ; the area of the admission port is about ^ of the piston
area ; accordingly the entering gases flow into the cylinder at a
velocity thirty times the piston velocity^ or at the Otto piston
speed, about 120 miles an hour.
Great commotion inevitably occurs ; the entering jet projects
itself through the gases right up against the piston, and then re-
turns eddying and whirling till it mixes thoroughly with whatever
may be in the cylinder. The mixture becomes practically homo-
geneous even before compression commences.
Experiments made by Dr. John Hopkinson and the author on
full size glass models of the Otto cylinder show this mixing action
very beautifully. A 3^ HP Otto cylinder was copied in every
proportion in glass, and the valve was so arranged that it passed a
charge of smoke at the proper time. The piston was placed at
the end of its stroke, leaving the compression space filled with air.
When pulled forward the valve opened to a chamber filled with
smoke, and the smoke rushed through the port, projected right
256 The Gas Engine
through the air in the space, struck the piston, and filled the
cylinder uniformly, much faster than the eye could follow it. It
mixed instantaneously with the air in the cylinder without evincing
the slightest tendency to arrange itself in the manner imagined
by Mr. Otto. Mr. Otto's experiment with a cigarette and glass
cylinder does not, in the most remote degree, imitate the condi-
tions occurring in his engine; the proportions are quite wrong.
The model is much too small, and the glass cylinder is too long
in proportion to its diameter ; then the gases are so badly throttled
by passing through the cigarette, that when the piston is moved
forward it leaves a partial vacuum behind it, and only a little
smoke enters, not nearly enough to follow up the piston, but
only sufficient to ooze into the back of the cylinder while the
piston moves forward and expands the air which is already in the
cylinder. It was easy for Mr. Otto to have copied his cylinder
and valve full size and imitated precisely the conditions existing in
his engines.
Had he done this he would have proved complete mixing in-
stead of stratification. Why did he refrain from doing this ? The
question at issue is not, Can stratification be obtained by a speci-
ally devised form of apparatus — no one doubts that it can — but,
Does stratification exist in the Otto engine? If it does not
exist in the Otto engine then it is perfectly plain that it cannot be
the cause of the economy of the motor, and it is quite certain that
it cannot exist in the Otto engine. Prof. Schottler, in the paper
already referred to, also arrives at the conclusion that stratification
has no existence in the Otto engine, and that Mr. Otto's small
glass model does not truly represent the actions occurring in the
engine,
In all gas engines, when the charge enters the cylinder through
a port the residual gases in the port are swept into the cylinder,
and while the port itself is filled with gas and air mixture, free
from admixture with residual gases, the cylinder contains the gas
and air mixture diluted with whatever residual gases exist in
the engine which have not been expelled by the piston. The
mixture in the port is accordingly stronger and more inflammable
than the mixture in the cylinder.
In the Lenoir and Hugon engines this occurred to a marked
Theories of Action of Gases in Modern Gas Engine 257
extent ; in the Hugon engine as much as 30 per cent, of the whole
charge consisted of residual gases, and the charge in the cylinder
was considerably more dilute than that in the admission port. In
the Otto engine this also occurs, but it is not stratification, and it
is not a new invention ; the cylinder is filled with explosive mix-
ture more dilute than that in the ignition port, but still explosive
throughout.
CAUSES OF THE SUPPRESSION OF HEAT AT MAXIMUM
TEMPERATURE IN GASEOUS EXPLOSIONS.
Although experimenters are unanimously agreed upon the fact of
the suppression of heat at the maximum temperatures produced by
gaseous explosions, they differ widely in their explanation of the
causes producing this suppression.
Three principal theories have been proposed —
1. Theory of Limit by Cooling. — This is Hirn's theory, and it
assumes that when explosion occurs, a point is reached when the
cooling effect of the enclosing walls is so great that heat is
abstracted more rapidly than it is evolved by the explosion, and
accordingly the temperature ceases to increase and begins to fall.
The maximum temperature falls short of what it would do if
no heat were lost during the progress of the explosion to the walls.
If it be true that the cold surface of the vessel is the limiting
cause, then the maximum pressure produced in exploding the
same gaseous mixture, in vessels of different capacity, will greatly
vary. When the vessel is small and the surface therefore re-
latively large, more heat should be abstracted and lower pressure
should be produced. This is not the case. The maximum tem-
perature produced by an explosion is almost independent of the
capacity of the vessel. Surface does not control maximum tem-
perature, although increased surface increases the rapidity of the
fall of temperature after the point of maximum temperature.
2. Theory of Limit by Dissociation. — This is Bunsen's theory,
and it is undoubtedly largely true. The fact that no unlimited
temperature can be attained by combustion, even when the use of
non-conducting materials prevents cooling almost completely, is
so conclusively established by science and practice that gradual
s
258 The Gas Engine
combustion due to dissociation may be safely taken as occurring
to a considerable extent at the higher temperatures used in gas
engines. But there is a difficulty in its application to all cases.
In experiments made with explosions in a closed vessel the
suppression of heat is almost the same at low temperatures as at
high temperatures ; thus with hydrogen mixtures —
Max. temp, of explosion 900° C. ; apparent evolution of heat 55 per cent.
,i ), » 1700° C. ,, ,, ,, 54 „
If dissociation were the sole cause, then as water must dissociate
more at the higher temperature than at the lower, the apparent
evolution of heat should be less at 1700° C. than at 900° C. It
is not so. Some other cause than dissociation must therefore be
acting to check the increase of temperature so powerfully at
900° C.
3. Theory of Limit by the Increasing Specific Heat of the Heated
Gases. — Messrs. Mallard and Le Chatelier have advanced the theory
that up to temperatures of about 1800° C. dissociation does not
act at all or only to a trifling extent. They consider that the
gases are completely combined or burned at the maximum
temperature of the explosion. But the specific heat of nitrogen,
oxygen, and the products of combustion increases with increasing
temperature, becoming nearly doubled when approaching 2000° C.
The apparent limit is due, not to the suppression of combustion
as required by the dissociation theory, nor to the loss of heat
by the theory of cooling, but to the absorption of the heat which
is completely evolved by the increasing capacity for heat of the
ignited gases. The same objection applies to this as to the
dissociation theory. If it were entirely true that specific heat
increased with increasing temperature, a greater proportion of
heat would apparently be evolved at the lower temperatures, which
is not always the case.
It is impossible to discriminate between the effect produced
by increased specific heat and the effect produced by dissociation
on the explosion curves.
Those are the three principal theories which have been pro-
posed, and in the author's opinion none of them completely explains
the facts. The phenomena of explosion are very complex, and
Theories of Action of Gases in Modern Gas Engine 259
no single cause explains the limit and other phenomena of
gaseous explosion. These phenomena are more complex than
have generally been supposed. In many chemical combina-
tions it has been proved by Messrs. Vernon-Harcourt and
Esson, and Dr. E. J. Mills and Dr. Gladstone, that the rate at
which the reaction proceeds depends upon the proportions ex-
isting between the masses of the acting substances present, and
those neutral to the reaction, and that combination proceeds
more slowly as dilution increases. From this it follows, that in a
combination where no diluent is present, the first part of the
action is more rapid than the last ; at first all the molecules in
contact are active, but after some combination has occurred the
product acts as a diluent. The last portion of the reaction,
having to proceed in the presence of the greatest dilution, is
comparatively slow. Such an action the author considers occurs
in all gaseous explosions, and is one of the causes preventing
the complete evolution of all the heat present at the moment of
the explosion.
The subject is a difficult one, and more experiment is required
for its complete settlement.
s 2
260 The Gas Engine
CHAPTER XL
THE FUTURE OF THE GAS ENGINE.
SINCE 1860, when by the genius and perseverance of M. Lenoir
the gas engine first emerged from the purely experimental stage,
it has steadily and continually increased in public favour and use-
fulness. At first more wasteful of heat than the steam engine, it
is now more economical ; at first delicate and troublesome in the
extreme, it is now firmly established as a convenient, safe and
reliable motor ; at first only available for small and trifling powers,
now really large and powerful motors are used in thousands.
Many inventors have contributed to its progress, but its present
position is in the main due to the patience, energy and command-
ing ability of one man — Mr. Otto.
In 1860, the efficiency of the gas engine was only 4 per cent; in
1886, the efficiency of the best compression engines is 18 percent.
That is, at first a gas engine could only convert 4 out of every
100 heat units given to it into mechanical work, as developed in
the motor cylinder ; now it can give 18 out of every 100 units as
indicated work.
Having advanced in economy more than fourfold in the past
twenty-five years, what limits exist to check its progress in the
future ?
Apart from the greater perfection of the mechanical arrange-
ments of the gas engines of to-day, the great cause of improve-
ment since 1860 is the successful introduction of the compression
principle.
Can this principle be much further extended in its application?
In the author's opinion, No.
By undue increase of compression the negative work of the
engine would be much increased, and the strains would become
The Future of the Gas Engine 261
so great that heavier and more bulky engines would be required
for any given power. Friction, due to this, increases more rapidly
than efficiency ; consequently the gain in indicated efficiency
would be more than compensated by loss of effective power. Im-
provement must be sought elsewhere.
The most obviously weak point of the present engine is insuffi-
cient expansion. In the Otto engine the exhaust valve opens
while the gases in the cylinder are still at a pressure of 30 pounds
per square inch above atmosphere ; in the Clerk engine the
pressure is sometimes as high as 35 pounds per square inch above
atmosphere at the moment of exhaust.
The gas engines discharge pressures, without utilising them,
with which many steam engines commence.
There is evident waste here, which can be remedied by using
further expansion. In continuing expansion the loss of heat to
the cylinder would not be so great as in the earlier part of the
diagram, because the temperature is greatly reduced ; it may
therefore be supposed, without appreciable error, that the added
portion of the diagram would give at least as good a result when
compared with its theoretical efficiency as the earlier part. If the
expansion be carried so far that the pressure falls to atmosphere,
then the theoretical efficiency of an Otto engine would be 0*5 ;
theoretically its cycle would then be able to convert 50 per cent,
of the heat given to it into indicated work ; practically the com-
pression gas engine at present converts one-half of what theory
allows ; therefore with the greater expansion it may be expected
to give one-half of 50 per cent. — that is, expansion only will raise
the practical efficiency from 18 per cent, to 25 per cent.
By complete expansion to atmosphere, the gas consumption
of an Otto or Clerk engine could be reduced from 20 cubic feet
per IHP hour, to 14*5 cubic feet per IHP hour. There are,
of course, practical difficulties in the way of expanding, but they
will be overcome in time. Mr. Otto has attempted greater ex-
pansion in various ways, and so has the author, but as yet neither
has succeeded in carrying it beyond the experimental stage.
It must not be supposed, as it too often is, that a high
exhaust pressure means an uneconomical engine, or that compari-
sons of pressure of exhaust give the smallest clues to the relative
262 The Gas Engine
economy of engines. It is a very common, but a very erroneous,
belief that if the pressure in the cylinder of a gas engine is very
near atmospheric pressure when the exhaust valves open, that
fact is a proof that the engine is economical.
This is not so — indeed, it may be the very reverse.
In engines of type 3, for example, in which, as in the Otto and
Clerk engines, the expansion after explosion is carried to the
initial volume existing before explosion and no further, it has
already been shown that the actual indicated efficiency is quite
independent of the increase of temperature above the temperature
of compression. That is, the temperature of the explosion may
be anything whatever above the temperature of compression with-
out either increasing or diminishing the indicated economy.
Suppose an Otto diagram with three expansion lines, (i) max.
temp. 600° C., (2) max. temp. 1000° C., and (3) max. temp.
1600° C., the maximum temperatures in the three cases being
attained at the beginning of the stroke, the efficiency of these three
lines is identical. Of course the total indicated power increases
with increase of temperature, and diminishes with diminution of
temperature, but the proportions of the heat given by the engine
as work in the three cases remain constant.
The same thing applies to any number of intermediate tern-
peratures.
It might be supposed that the line i by expanding more nearly
to atmosphere would be the more economical, and that the line 3,
because of the high pressure of exhaust, was the more wasteful.
It is a peculiarity of this cycle, with the expansion stated,
that the efficiency is absolutely dependent upon compression
alone — that is, the ratio of volume before and after expansion — and
is quite independent of the maximum temperature.
The case at once alters if expansion be carried to atmosphere.
Here the line 3 would give far greater economy than the others,
and efficiency would increase with increase of explosion tempera-
ture.
Suppose complete expansion successfully applied to the gas
engine, and an actual indicated efficiency of 25 per cent, attained,
can any further improvement be hoped for ?
What causes the difference still existing between theory, which
The Future of the Gas Engine 263
shows a possible 50 per cent., and practice, which may now realise
25 per cent. ?
The great loss is heat flowing from the exploded gases through
the cylinder walls. Dr. Slaby's balance-sheet of the Otto engine
shows —
Per cent.
Work indicated in cylinder . . . . . 16'c-
Heat lost to cylinder walls . . . .51-0
Heat carried away by exhaust . . . . 31 'o
Heat lost by radiation, etc. ,. . • !.. . a'o
100
By expanding as described it would be altered as follows ;
Per cent.
Work indicated in cylinder . . . . . 25 'o
Heat lost to cylinder walls . . . . ."51-0
Heat carried away by exhaust . . . . 22 'o
Radiated loss, etc ' . 2-0
The work done will be increased by diminishing the loss of
heat with the exhaust gases, but the loss of heat to the cylinder
walls will remain constant. This assumes, of course, that the in-
creased time of expansion is balanced in loss to cylinder walls by
more rapid rate of fall ; if the piston velocity is not increased the
result will not be quite so good. If, for instance, the piston
velocity is constant, and the volume to surface ratio is constant,
the expansion will only give results as follows :
Work indicated in cylinder 21 'o
Heat lost to cylinder walls and radiated . .66-5
Heat carried away by exhaust . . . .12-5
100 'O
Expansion so arranged as to be equivalent to the same time of
present piston stroke, o'2 seconds, by increasing piston velocity and
rearranging cooling surfaces, will give 25 per cent, of total heat in
indicated work : if surfaces and piston speed remain unaltered, so
that the time of exposure increases in same ratio as expansion,
then 21 per cent, only will be attained. With proper expansion,
the loss of heat by the exhaust gases discharging at a high temper-
ature may be greatly diminished, and the efficiency would be
increased, but the change would not affect the loss of heat to
cylinder walls • it would even increase it.
264 The Gas Engine
How can this, the greatest loss in the gas engine, be reduced ?
The loss depends, as has already been stated, upon the ratio of
surface to volume of gases exposed to cooling, upon the time of
exposure, and upon the elevation of the temperature of the hot
gas above the enclosing surfaces cooling it.
It is evident that as engines increase in power, the capacity
of cylinders of similar proportions increase as the cube of the
diameter, while the area of the enclosing cold surfaces increases as
the square of the diameter. As engines of greater and greater
power are constructed, the surface exposed in proportion to volume
becomes less and less ; the loss of heat from this cause will, there-
fore, diminish.
Increase in piston velocity will also diminish loss, by diminishing
time of contact : 300 feet per minute is the usual speed at present,
and it cannot be advantageously increased in small engines, as the
reciprocations of the parts become too frequent for durability : but
in large engines with diminishing reciprocation, the piston speed
may be increased to 600 feet per minute, and still be within the
limits practised in steam engines.
Increase in temperature of cylinder walls is also advantageous
within certain limits. The author has found a difference of as
much as 10 per cent, upon the consumption of gas of an Otto
engine when at 17° C., and so hot that the water in the jacket was
just short of boiling 96° C. It is probable that still higher
temperature could be advantageously used, but there is a limit
imposed both by theory and practice.
However, the cycle could be modified to permit the use of
very hot walls, enclosing the gases at 500° C.
When all these precautions against loss are practised in large
engines, and the heat loss is greatly reduced, another complication
steps in, which modifies the theory of the engine very considerably.
That complication is the property possessed by all explosive
gaseous mixtures of suppressing part of their heat—the phe-
nomenon of Dissociation, the * Nachbrennen ' of the Germans, or
the apparent change of specific heat or continued combustion of
the French and the English.
Although a gaseous explosion expanding in a cold cylinder
behind a piston doing work very nearly follows the adiabatic line,
The Futtire of the Gas Engine 265
yet if expanded under such circumstances that the loss of heat
was greatly diminished, it would no longer do so.
In large engines the expansion curve is always above the adia-
batic ; in small engines it is below the adiabatic.
In fig. 53, diagram taken by Professor Thurston, if all loss of
heat to the cylinder could have been prevented, the expanding
line would have been an isothermal, the maximum temperature of
1657° would have been sustained to the end of the stroke, and the
actual efficiency of the diagram would have been 0-40, that is,
40 per cent.
At the point 7 the temperature would be 1657°, and the gases
would still contain 60 per cent, of all the heat given to them, and if
expanded to atmosphere adiabatically, the combustion being sup-
posed complete, then 13 per cent, would be added, making a
total efficiency of 53 per cent.
If the loss of heat through the cylinder could be totally sup-
pressed, the possible efficiency, taking into consideration the
properties of explosive gases is 53 per cent. It is impossible to
completely avoid loss to the cylinder, but it will doubtless be
greatly reduced.
The united effect of expansion, greater piston speed and reduc-
tion of loss of heat to the cylinder by using hot liners, when carried
out in an engine of considerable power, would cause the attainment
of a practical heat efficiency of at least 40 per cent, and this with-
out any great change in the construction of gas engines now made.
Now, how do these efficiencies compare with those of the steam
engine? It is generally admitted that the best steam engines
of considerable powers and of the latest type, when in ordinary
work do not give an efficiency greater than 10 per cent., that is,
they do not convert more than 10 per cent, of the heat given to
the boiler in the form of fuel, into indicated work. In small engines
of such powers as are comparable with the largest gas engines yet
constructed, the results • are not nearly so good, an efficiency of
4 per cent, being a good result.
The reader will remember that the term efficiency, as used in
this work throughout, is defined to mean the proportion of heat
converted into work, to total heat given to the heat engine.
Efficiency is often used in another sense, and considerable
266 The Gas Engine
confusion has arisen because of its use in different senses by diffe-
rent writers. In comparing engines differing in their nature, the
only standard of comparison possible is the total heat or total fuel
given to each engine, and the proportion of total heat or total fuel
which that engine can convert into work. The source of power is
always combustion, and the temperature of combustion may always
be supposed to be the superior limit of temperature whatever the
working process, whether steam or air is the working fluid. From
the fact of taking the total heat as the basis of comparison, the
reader is not to infer that it is possible even in theory to convert
all of it into work. Professor Osborne Reynolds, in a lecture be-
fore the Institution of Civil Engineers, stated that this seemed to
be a belief popular among engineers ; the author does not think
that this is so.
Certainly, the second law of Thermodynamics is not so widely
understood among engineers as it should be, but still, few suppose
that it is even theoretically possible to convert all the heat given
to an engine into work.
In the discussion on the author's paper on 'The Theory of the
Gas Engine,' at the Institution of Civil Engineers, considerable
confusion arose from the term efficiency being used in different
senses by different speakers. Professor Fleeming Jenkin in his
lecture very clearly defines the different legitimate uses of the
term.
Returning to the comparison of gas and steam engine heat
efficiency, the 10 per cent, of the steam engine is probably very
nearly as much as can be ever attained \ it may be exceeded by
using high pressures and great expansion, but it will never be pos-
sible to attain anything like 20 per cent. The limits of tempera-
ture are such that if the steam cycle were perfect, only 32 percent,
of the whole heat could be converted into work ; at the boiler
pressures and condenser temperatures used, the theoretical effi-
ciency of the steam engine cycle is within 80 per cent, of the cycle
of a perfect engine, that is, the efficiency theoretically possible is
32 x 0-8 = 25-6 per cent. In an experiment made by Messrs.
B. Donkin & Co. on a 63 HP compound engine, the results as
given by Professor Cotterill in his work on the steam engine are
as follows :
The Future of the Gas Engine 267
Per cent.
Absolute efficiency ii'i
Efficiency of a perfect engine . . . . 28-4
Relative efficiency . . . . . . 39'!
The engine received 100 heat units from the boiler as dry
steam, and it gave 11*1 units as indicated work in the cylinder.
With the pressures and temperatures given, the steam engine cycle,
if perfectly carried out, falls short of the cycle of a perfect heat
engine between the limits, so that 227 per cent, is the maximum
efficiency which could be obtained, supposing no other loss than
that due to the imperfection of the cycle. The cylinder losses,
condensation, incomplete expansion and misapplication of heat,
make the actual indicated efficiency ii'i per cent, so that half
has gone. The furnace loss diminishes the absolute efficiency to
9*2 per cent, and it is extremely improbable that improvement
can ever increase this to 18 per cent., which is the indicated
efficiency of the gas engine as at present.
It is impossible that the steam engine can ever offer an effi-
ciency of 40 per cent., which is quite possible with the gas engine.
What remains to be done, then, in order to make the gas
engine compete with steam for really large powers ? At present
the largest gas engines do not indicate more than 40 HP, and
very few are in use so powerful.
The gas engine, although superior in efficiency as a heat
engine to the steam engine, is not superior in economy except for
small powers, where steam engines are very wasteful and the cost
of attendance relatively great
The unit of heat supplied in the form of coal gas is more
costly than the unit of heat supplied in the form of coal. Gas
producers are required which will convert the whole of the fuel
into gas as readily as steam is produced, and with no greater loss
of heat than a boiler has.
Mr. J. E. Dowson's producer is the only one at present in
existence giving suitable gas, and it requires the special fuel
anthracite.
The use of ordinary fuel has not yet succeeded.
A good gas producer, giving gas usable and free from tar, is
much wanted.
268 The Gas Engine
But when all this is done, the gas engine remains in some
respects inferior to the steam engine. It would then be a great
advance in economy, as it is at present much superior as a heat
engine, or machine for the conversion of heat into work. But
mechanically it would still be inferior to steam.
As a piece of mechanism, the steam engine is almost perfect :
it is started, stopped, and regulated in a very perfect manner. Its
motion is, in good examples, almost perfectly uniform under
variation of load, and but little fly-wheel power is required, be-
cause there is little or no negative work.
Its motion is perfectly under control.
The gas engine itself requires much improvement in this re-
spect ; it is a comparatively inferior machine ; at best it receives
only one impulse every revolution when at full power, and when
under light loads only an occasional impulse.
Means must be found to make it double acting, and to
diminish the power of the impulses instead of diminishing their
frequency for governing.
Means must also be found to start and stop as in steam
engines ; the present starting gear is a step in this direction, but
requires development.
All this can and will be done; it is a matter of time and
patience. It can and will be made as mechanically perfect and
controllable as the steam engine. Flame and explosion, seemingly
so untameable and destructive, have been to a great extent tamed
and harnessed in present engines. Experience is growing, by
which it will be as easily and certainly directed in the cylinder of
an engine as steam is at present. The furnace, at present sepa-
rated from the engine, will be transferred to the engine itself, and
the power required will be generated as required for each stroke,
and the system of storing it up in enormous reservoirs — steam
boilers — finally abandoned.
The masses of smoke polluting our atmosphere will be entirely
abolished so far as motive power is concerned.
The author cannot do better in conclusion than quote the
late Professor Fleeming Jenkin, expressing his belief in the future
of this form of motor.
' Since that is the case now, and since theory shows that it is
The Future of the Gas Engine 269
possible to increase the efficiency of the actual gas engine two or
even threefold, then the conclusion seems irresistible, that gas
engines will ultimately supplant the steam engine. The steam
engine has been improved nearly as far as possible, but the
internal-combustion gas engine can undoubtedly be greatly im-
proved, and must command a brilliant future. I feel it a very
great privilege to have been allowed to say this to you, and I say
it with the strongest personal conviction.'
2; i
PART II.
GAS ENGINES PRODUCED SINCE 1886.
CHAPTER I.
GAS ENGINES GIVING AN IMPULSE FOR EVERY REVOLUTION.
THE first part of this work was published in 1886, and the
account of the different engines described is accurate up to that
date ; - the scientific part of the work, dealing with the thermo-
dynamics of the gas engine, and the various causes of loss
operating in working engines, is as true to-day as when written,
and requires no modification.
The ten years elapsing between 1886 and the present year
have however, seen many important changes in details of con
struction, and a considerable advance has been made in the
construction of large gas engines. Gas producers have been
more extensively adopted; petroleum engines have been pro-
duced which are practically useful, although not quite so well
understood as gas engines ; very effective and simple starting
gears have been invented and extensively applied ; the slide
valve igniters have been practically abandoned, and the hot tube
igniters have taken their place ; the compound principle has
been advanced a stage ; and generally the gas engine has been
made as reliable in its action as any steam engine.
The Otto patent of 1876 (No. 2081) expired in 1890, and
this event has had a most important effect on the gas engine
from a commercial point of view ; so many engineers now make
Otto cycle engines that the selling price for any given power
has fallen from 40 per cent, to 50 per cent, as compared with
1886 prices. So far this fall in prices has had one good effect,
272 The Gas Engine
and has greatly increased the number of gas engines in use, by
bringing the cost within the means of many small manufacturers
formerly unable to stand the considerable first cost of a gas
engine.
The lapse of the Otto master patent has, however, had
another effect which may prove an obstacle in the development
of the gas engine. In Britain the Otto cycle engine is now
practically the only engine manufactured ; the whole of the
impulse-every-revolution engines have disappeared from the
market ; many are still in successful work, but their makers
with wonderful unanimity have ceased their manufacture, and
have generally taken to the construction of Otto engines. At
the present time practically the whole of the engines manufactured
and offered for sale in this country by engineers are engines
operating on the Otto cycle, giving one impulse for every four
single strokes of the piston.
This state of affairs offers emphatic testimony to the practical
advantages of the Otto cycle, and in the author's opinion engi-
neers are correct in considering the Otto cycle as likely to remain
unrivalled for small and perhaps moderate power gas engines.
For really large engines, however, it appears to him that the
Otto cycle is inherently defective, and he still considers impulse
every revolution or two impulses per revolution as much prefer-
able, and as certain to prove the type of the future for really large
power engines. It is therefore much to be regretted that for the
present engineers have practically ceased their efforts in the
direction of more frequent impulses, and have devoted them-
selves entirely to the development of the Otto type.
The following are the leading makers of Otto cycle gas
engines in Britain :
Messrs. Crossley Bros., Limited, Manchester ; Messrs. J. E. H.
Andrew & Co., Limited, Reddish ; Messrs. T. B. Barker & Co.,
Birmingham ; Messrs. Tangyes, Limited, Birmingham ; Messrs.
Dick, Kerr & Co., Limited, Kilmarnock ; Messrs. Robey & Co.,
Limited, Lincoln ; Messrs. Fielding & Platt, Gloucester ; and
Messrs. P. Burt & Co., Glasgow.
There are many other engineers who manufacture good Otto
cycle engines, but a description of engines by several of these
Gas Engines giving an Impulse for Every Revolution 273
makers will put the reader in full possession of the leading points
of recent gas-engine practice. Before beginning the Otto cycle
engines, however, it is advisable to consider shortly the position
of impulse-every-revolution engines from 1886.
Atkinson's ' Cycle ' Gas Engine. — The most important of the
engines giving an impulse every revolution produced since the
year 1886, was undoubtedly the engine called by Mr. Atkinson
the * Cycle.' At page 197 of this work will be found a description
of Atkinson's Differential Gas Engine, in which a most ingenious
attempt was made to obtain greater expansion than was given in
Otto engines. To a certain extent this attempt was successful,
and the combustible mixture was expanded after explosion to a
volume considerably greater than the volume existing before
compression. Considerable economy was obtained in the engine,
but certain practical difficulties intervened which caused Mr.
Atkinson to invent another engine quite as ingenious, but
having one piston instead of two.
The engine is shown in longitudinal section at fig. 102, in plan
at fig. 103, and at fig. 104 at i, 2, 3 and 4 are given the four
principal positions of the linkage and piston, carrying into effect
the operations of the engine. The piston makes two out and two
in strokes for every explosion given, and in this feature the engine
resembles the Otto, but here the resemblance ends. The piston
is so coupled to the crank shaft that the whole four single strokes
are performed during one revolution ; and, moreover, the four
strokes differ in length and range in the cylinder, so that while
on one in-stroke the piston proceeds almost entirely to the end of
the cylinder to sweep out practically the whole of the products of
combustion, on the next in-stroke it stops short and leaves a con-
siderable compression space ; on one out-stroke also a short
distance is traversed, and on the other out-stroke a longer stroke
is made to obtain greater expansion. That is, during the exhaust-
ing in-stroke the piston moves close up to the cylinder cover ;
during the compressing in-stroke it leaves a considerable space ;
during the expanding out-stroke after explosion the piston makes
its longest sweep ; and during the charging out-stroke it makes a
shorter sweep.
T
274
The Gas Engine
'/7WVVVV
FIG. 102. — Atkinson Cycle Engine (longitudinal section).
FIG. 103.— Atkinson Cycle Engine (plan).
Gas Engines giving an Impulse for Every Revolution 275
By these variations in length of stroke and position of sweep
in the cylinder, the piston not only sweeps out the whole of the
products of combustion, but it also expands the burned gases
beyond the volume existing before compression. The linkage
invented by Mr. Atkinson to perform these operations is ex-
tremely simple and ingenious^ and will be best followed by an
examination of the diagrammatic illustration i, 2, 3 and 4 of
fig. 104.
The cylinder A contains the piston B, which piston is con-
nected to the crank c, which rotates in the direction of the arrow
5 : the connecting rod D from the crank c connects to a toggle
lever E, pivoting from the fixed centre 6, at the centre 7 ; the
•connecting rod D carries a short lever D1 rigidly attached to it
and carrying a pin or centre 8, and to this pin or centre 8 is con-
nected the second connecting rod or toggle link F. By the
rotation of the crank c, the toggle lever E is constrained to
oscillate on its pivoting point or centre 6, between the limits
shown by the dotted lines 9 and 10. The centre 7 of the con-
necting rod D and lever E thus describes the arc shown by the
dotted line between the lines 9 and 10, and if the rod F were con-
nected to the centre 7 the piston B would make two out and two
in-strokes for every revolution of the crank c, and the two strokes
would be of equal or unequal length depending on the equal or
unequal oscillation of the toggle lever E about a central position
with regard to the connecting rod F, but in this case the in-stroke
of the piston B would always terminate at the same point, and so
one stroke could not be arranged to clear out the exhaust gases,
while another left the required compression space. To produce
this desired variation, Mr. Atkinson provides the short lever D1
which oscillates about the centre 7, describing an arc between the
dotted lines n and 12 about the centre line of the lever E. The
position of the centre 8 relative to the centre line of E depends on the
position of the crank c in the crank circle, and the angle between
the lines 1 1 and 1 2 depends upon the relative length of the con-
necting rod D, as compared with the diameter of the circle
described by the crank c, and also the angle between the lines 9
and 10.
In diagram i (fig. 104) the piston B is at its extreme in
T 2
276
The Gas Engine
Duuyr&m I
FIG. 104. — Atkinson Cycle Engine
(four positions of linkage).
position, and all products
of combustion have been
expeiled; the crank c ro-
tates in the direction of the
arrow 5, and in diagram 2
the piston B has made its.
out charging stroke, taking
into the cylinder a charge
of gas and air at atmospheric
pressure. It is to be ob-
served that in diagram 2
the piston B, although at
the end of its charging
stroke, still remains within
the cylinder A ; in diagram
3 the crank c has still
further rotated, and now
the piston B has. attained
the extreme in-end of its
compression stroke, the
mixed gases are fully com-
pressed and ready for ex-
plosion, the explosion takes
place at the position shown
in diagram 3, and the crank
c continuing to rotate, the
parts at the extreme out-
ward position of the piston
B after expanding the gases
assume the position of dia-
gram 4. In this latter
position it will be observed
that the piston B has tra-
velled somewhat out of the
cylinder A, that is it has
made a longer stroke than
the compression stroke.
The stroke made in passing
Gas Engines giving an Impulse for Every Revolution 277
from the position of diagram 4 to that of diagram i is the longest
of all strokes, as in it the piston passes from the extreme out-
position of expansion right into the cylinder cover, and sweeps
out all the products of combustion. The next out-stroke is
shorter, taking in the charge ; the following in-stroke is shorter
still, compressing the charge and leaving a compression space ;
then follows the longest out-stroke, that of expanding the gases
after explosion. A comparison of diagrams i and 3 shows the
reason of the difference of position of the piston B ; although in
both cases the toggle lever E is in practically the same position,
in i the crank c is on one side of the crank circle, while in 2 it is
on the other side, so that the lever D is thrown from the top of
the centre line of the toggle lever E to a position under it, but the
effect of the movement is to draw the piston forward from the
•cylinder cover. By studying the positions of the lever D and the
positions of the toggle lever E from the diagrams, the action will
be readily followed.
In the engine rated at 6 HP nominal, the cylinder is 9*5 ins.
-diameter, and the four successive strokes are as follows :
ist (out-stroke) Suction of gas and air charge . 6*33 ins.
2nd (in-stroke) Compression of charge . . . 5*03 ins.
3rd (out-stroke) Working expansion after explosion 11*13 ins-
4th (in-stroke) Discharging exhaust . . . 12 '43 ins.
The construction of the 6 HP engine is shown at figs, 102 and
103 in longitudinal section and elevation ; A is the cylinder ; B
the piston ; c the crank ; D the connecting rod to the toggle lever ;
E the toggle lever ; D1 the short connecting rod lever ; F the con-
necting rod between the piston and the pin 8 on the lever D1 ; G is
the water jacket surrounding the cylinder and fitted with the usual
openings for pipe connections to the tank ; H is an incandescent
igniting tube, open to the cylinder, and arranged to operate with-
out timing valve in a manner to be described later on ; i is the
exhaust valve ; and K the gas and air inlet valve (shown in plan,
fig- IO3) ) L is tne gas valve. All three valves are of the usual
conical-seated lift type held on their seats by springs, and they are
operated from the crank shaft by cams i1 K1, and rods i2 K2, in
the usual way. The governor is indicated at L1, and it is of the
rotating centrifugal type ; it acts on a rod connecting between the
2? 8 The Gas Engine
actuating cam and the gas valve stem to cause the end of the rod to
be withdrawn, and the gas valve stem missed, so leaving the gas
valve closed for a stroke or a number of strokes. This also is a
common device.
Diagrams and Gas Consumption. — A test of the first ' Cycle ''
engine constructed was made in April 1887 by Professor W. C.
Unwin, F.R.S., for the British Gas Engine Co., Ltd., the makers
of the engine in London.
The engine was rated at 4 HP nominal, the diameter of the
cylinder 7*5 ins. and the expansion or working stroke 9*25 ins.
The leading results obtained were as follows :
Indicated Horse Power 5*563
Brake ,, ,, ..... 4-889
Gas consumed in one hour ..'... 100 cb. ft.
Gas consumption per IHP per hour . . . 1978 cb. ft.
Gas consumption per brake HP per hour . . 22*50 cb. ft.
Efficiency of mechanism 87-9 per cent.
Heating value of gas in Ibs. degree C° per cb. ft. . 349*3
Professor Unwin accounts for every 100 heat units used by
the engine as follows :
Accounted for in indicator diagram .... 20*62
Given to jacket water i9'37
Difference, exhaust gases, radiation, &c. . . . 6o'i
An indicator diagram taken during the test is given at fig. 105,.
and in dotted lines on the same diagram is one taken by Dr. Slaby
from a 4 HP Otto engine. This latter diagram was taken by
Dr. Slaby during a test referred to at page 170 of this work.
The ratio of the expansion in the Otto engine was 27 as com
pared with 3*75 in Atkinson's ; that is, in the Otto engine, the
volume of the compression space being taken as i, then the total
volume behind the piston, when the piston was full out, was
27 volumes ; the sweep of the piston was therefore 17 times the
volume of the compression space ; in the Atkinson engine, the
volume of the compression space being i, the volume swept by
Gas Engines giving an Impulse for Every Revolution 2/9
the piston during expansion was 2*75 ; the gases contained in
the compression space were thus expanded from i volume to
375 volumes. In the author's opinion, Professor Unwin's
diagram fig. 105 is hardly fair to the Otto engine, as it appears
to somewhat exaggerate the amount of expansion obtained in the
cycle engine as compared with the Otto, and the diagram should
be so corrected as to allow for the differing combustion spaces.
The expansion, however, in the Atkinson engine is doubtless much
greater than in the Otto, and accordingly the gases fall to a
FIG. 105.— Atkinson Cycle Engine (Prof. Unwin's diagram).
pressure of about 1 5 Ibs. per square inch before the exhaust valve
is opened.
An important series of tests were made by judges appointed
by the Society of Arts, Dr. John Hopkinson, F.R.S., Professor
A. B. W. Kennedy, F.R.S., and Mr. Beauchamp Tower, at South
Kensington in 1888, of the Crossley, Griffin, and * Cycle' gas
engines, from which it appeared that the Atkinson ' Cycle ' gave
distinctly the lowest gas consumption. The principal results
obtained were as follows :
280
The Gas Engine
SOCIETY OF ARTS TRIAL.— ATKINSON ENGINE.
Indicated Horse Power . . . . . 11*15
Brake ,, ,, 9-48
Gas consumed in cylinder in one hour . . 209-8 cb. ft.
Gas consumed for ignition in one hour . . 4-5 cb. It.
Gas consumption per IHP per hour total . . 19-22 cb. ft.
Gas consumption per brake HP per hour total . 22-61 cb. ft.
Efficiency of mechanism 85 per cent.
Heating value of gas in Ib. degree C., per cb. ft. 351*6
Revolutions per minute 131*1
Explosions per minute 121 *6
Mean initial pressure, above atmospheric . .166 Ibs. per sq. in.
Mean effective pressure 46-07 Ibs. per sq. in.
Cooling water per hour 680 Ibs.
Rise of temperature cooling water . . . 50° F.
The engine was rated at 6 HP nominal ; the cylinder was
9-5 inches diameter ; suction stroke 6-33 inches ; compression
stroke 5-03 inches ; working or expansion stroke 11-13 inches;
and exhaust stroke 12*43 inches.
The test giving these figures was of 6 hours' duration, and
the engine was continually loaded to full power ; indicator dia-
grams were taken every 15 minutes, and diagrams were also
taken with light springs to find
Mean Pressure ^eis the power absorbed in the pump-
Revotutions per mm 73050 . . . r _5
Explosions ., ., izo 7' mg and exhausting strokes, rig.
1 06 is a diagram taken during
this trial, and the leading par-
ticulars are marked upon it.
Fig. 107 shows an ideal dia-
FIG. 106. -Atkinson Cycle Engine gram superposed upon an actual
(Society of Arts diagram). diagram; the ideal diagram is
the one assumed by the judges in
the Society of Arts trial as fairly corresponding with the actual
conditions, lines have been straightened out, and curves made
to follow a different law in order to obtain approximately correct
figures for temperatures and heat volumes. Standard points
A, B, c, D, E, F, and G have been taken, and the volumes
existing behind the piston accurately measured at the various
points. The point A, for example, represents the farthest in
point when the piston is full back, discharging the products of
Gas Engines giving an Impulse for Every Revolution 281
•combustion. The piston moves out from A to B, taking in the
charge of gas and air • the piston then returns from B to c, com-
pressing the charge to the pressure and volume indicated. The
explosion then occurs, and during the rise of pressure and tem-
perature the piston is supposed to be stationary, that is the volume
behind the piston is the same when the pressure attains its
maximum as indicated at D as at the point c, so that the heat
added by the explosion is added when the gases are at constant
volume ; from D to E the
piston is supposed to move
out while the pressure remains
-constant, that is the heat added
from D to E is added at con-
stant pressure. The hot gases
are supposed to expand from
E to F, following truly a de-
finite curve in which pvn =
constant. In the diagram n
is taken as 1-264, and the
curve E F has the equation
pv\-i§\ — constant.
The value of n for the
compression curve is 1*205,
and assuming the specific heat
of the charge the same as that
of air, which assumption is
very nearly true, then the value
of n should be 1*408 ; the
curve of compression in this
diagram is therefore below the adiabatic, and the charge is losing
heat to the sides of the cylinder during compression.
The value of n for the expansion line E F is i '264, which proves
the curve to be much flatter than would have been given by the
adiabatic expansion of a volume of air heated to the maximum
temperature at E. The ratio of the specific heats of the expand-
ing charge at constant pressure and constant volume has been
calculated by the judges as 1*376 on the assumption of the pre-
sence in the charge of the products of complete combustion.
01 0-2 0-3 0-+
ATKINSON ENGINE
FIG. 107. — Atkinson Cycle Engine
(Society of Arts actual and ideal
diagram).
282
The Gas Engine
This in the author's opinion is a quite erroneous assumption, as-
only about one-half of the total heat of the gas present is accounted
for by the maximum temperature, so that the specific heat could
not change to the extent assumed ; the value of n, however, for
the expanding charge is somewhere between 1*376 and 1-408, so
that the error introduced is not great.
The following table gives the pressure, volumes, and tem-
perature at the various points of the ideal diagram, fig. 107 :
Pressure,
5. persq. in. absolute
Volume
in cub. feet
Temperature,
degrees C.
14-87
0-064
14-87
0-324
46-6 C.
5° '30
0-118
126-4 C.
> itfo'90
O'ii8
1182-5 C.
180-90
o'i35
1388 i C.
29-00
o'575
849-2 C.
]f 14-87
o'575
849-2 C.
The report gives full calculations of heating value of the gas
used, specific heat of products of combustion, and many other
details ; several of these matters will be more fully discussed later
on, in comparing the results obtained from different engines.
It is desirable to note here, however, that the ratio of air to-
gas entering the cylinder is calculated as i volume gas to
9-33 volumes of air. It is unfortunate that the ratio was not
determined by independent measurement of both gas and air by
separate meters, as was done in Professor R. H. Thurston's
American test, described on page 175 of this work. Comparing
the proportions of coal gas and air plus other gases present, it
is interesting to note that in Thurston's experiments the entering
charge contained i volume of gas to 7 volumes of air, but when
mixed with the products of combustion in the compression space
the average composition was i volume coal gas to 9*1 volumes of
other gases. The composition of the mixture in the two cases
thus appears to be practically the same. In the Otto engine,
however, the temperature of the charge was much higher before
compression than in the Atkinson engine, as was also the tern-
Gas Engines giving an Impulse for Every Revolution 283
perature of compression ; the maximum temperature of the ex-
plosion would appear to be higher in consequence.
The report gives the heat account of the foregoing test as
follows :
Per cent.
Heat turned into work as shown by indicator diagrams '. . 22 '8
Heat rejected in jacket water . .. . . «' ' ..• . ,. . . 27 -o
Heat rejected in exhaust, lost by imperfect combustion, and
otherwise unaccounted for . . • . . . . 50 '2
This gas consumption of 19*22 cub. ft. per IHP per hour,
giving an efficiency of 2 2 -8 per cent, was the best result so far as
economy was concerned up to the date of the trial, September
1888.
General Remarks. — The Atkinson ' Cycle ' engine was manu-
factured and sold by the British Gas Engine Company, London,
from 1887 to the beginning of 1893, and during that period the
author is informed that somewhat over 1,000 gas engines were
sold j the engine, however, notwithstanding the great ingenuity
of its construction and its unrivalled economy of gas consump-
tion, never became really popular. Difficulties were experienced
with the linkage, which had at least five working pins as compared
with the two pins of the ordinary connecting rod, and these diffi-
culties ultimately led the inventor to return to an engine of less
uncommon construction, having only the ordinary crank and
connecting rod.
Mr. Atkinson, however, in his ' Cycle ' engine proved absolutely
the possibility of obtaining great economy in gas consumption by
expanding the gases after explosion to a volume much greater
than existed before compression. By his ingenious linkage he
caused one piston to perform four strokes within one revolution
of the crank shaft ; he also proved conclusively a point for which
the present author has long contended — namely, that better
results are to be obtained in a gas engine by expelling the whole
of the products of combustion from the cylinder than by retaining
them.
The ' Cycle ' engine has a very high piston speed for a given
number of revolutions of the crank shaft, as each complete stroke
284 The Gas Engine
of the piston was accomplished in about one -quarter revolution,
as will be clearly seen by inspecting the diagram, fig. 104. This
high piston speed, although advantageous so far as gas consump-
tion was concerned, must have been detrimental to the smooth
and long-continued satisfactory working of the engine, as the
movements of the piston rods and links were of a kind which
could not be conveniently balanced.
The engine was made in sizes up to about 30 HP brake, and
the author understands that one 100 HP engine was constructed,
but he is informed that this size was never placed on the market.
Atkinson's ' Utilite' Gas Engine. — This engine was invented
by Mr. Atkinson with the object of retaining all the economy of
the ' Cycle ' gas engine, while returning to the ordinary mechanical
arrangement of piston, crank, and connecting rod, which has had
the sanction of engineers and the public, inasmuch as it is prac-
tically the only construction adopted in steam engines.
The linkage of the ' Cycle ' engine, although most admirable
from an experimental point of view, was not such as an engineer
would care to adopt in a high-speed or even a high-power engine,
and although it served its purpose by proving to demonstration
many interesting points, yet the present author was much pleased
to see Mr. Atkinson depart from it.
The ' Utilite ' engine never attained any real commercial im-
. portance, as the British Gas Engine Company gave up business
shortly after they had begun its manufacture. The Otto cycle
had just then taken so firm a hold upon the public, that it
appeared useless to sue for popular favour with any impulse-every-
revolution engine, however good.
The engine is of the greatest interest to engineers, however, as
it proves how great economy can be obtained with an impulse-
every-revolution engine.
The 'Utilite ' engine resembles in many points the Clerk and
Robson engines. One side of the piston operates as a pump and
pumps air into a chamber at low pressure, from which it flows
through a valve into the power side of the cylinder, and displaces
the exhaust gases before it through a port or ports uncovered by
the forward movement of the piston. The cylinder thus contains
Gas Engines giving an Impulse for Every Revolution 285
a quantity of air, which is compressed by the piston on its return
stroke, and charged during compression with a charge of gas and
air mixture, the gas, however, in the mixture being present in
proportion too great to be explosive.
The trunk piston operates in the cylinder connected to the
crank shaft by the connecting rod. The whole front of the
cylinder and the rod and crank shaft are inclosed within a casing,
and a back cover is arranged to contain the compression or ex-
plosion space. A chamber or casing connects by a pipe with
an automatic inlet valve, and another automatic inlet valve admits
air to the casing or chamber. A pump is operated by an eccentric
on the crank shaft, and it takes in a charge of gas and air by way
of a valve and the gas cock, and discharges the charge at the
proper time by way of the valve. The piston overruns the exhaust
port at about half-forward stroke, and the port is controlled by a
piston valve, so that, although the piston uncovers the exhaust
port at mid-stroke, yet the exhaust gases are not discharged to
the atmosphere till the exhaust valve is opened at the termination
of the out-stroke.
The action of the engine is as follows : On the in-stroke the
piston draws into the chamber a charge of pure air by way of the air
valve, and on the out- stroke it compresses this charge to a pressure
of about 5 Ibs. per square inch. When the piston is full forward,
then the exhaust valve is opened, and the pressure within the
working cylinder falls to atmosphere and the pressure in the
chamber lifts the charge valve, and air rushes by way of a pipe
through the charge valve and enters the cylinder, clearing before
it the exhaust gases through the exhaust port and valve, which is
then open. The piston then returns, discharging the rest of the
exhaust gases through the port until the piston crosses that port,
when it begins to compress the air charge. Just as the port is
closed, the gas and air pump begins to discharge its contents, a
mixture of air and gas, into the combustion space of the cylinder
by way of the gas and air valve. The gas and air mixture in the
pump has too little air to make the charge explosive, and so it is
impossible for the mixture to ignite in the pump. The gas being
already mixed with air only requires the addition of a further
quantity to become explosive, so that by the time the charge is
286 The Gas Engine
compressed the gas is almost uniformly mixed with the air, and
is in a state to produce a powerful explosion. The mixture
is expanded by this arrangement to a volume after explosion
and expansion much greater than the volume existing before
compression, and so considerable advantage is obtained in
economy.
The cycle of operation of this engine is very similar to that of
previous engines, but Mr. Atkinson, by his thorough knowledge
of gas engine detail, has obtained results, he informed the author,
which have surpassed those previously obtained with the cycle
engine. The author regrets that he has been unable to obtain
authenticated tests and diagrams of this engine.
Other Impulse- Every -Revolution Engines. — The other impulse-
every-revolution engines which have appeared since 1886 are :
The Campbell Gas Engine, manufactured by the Campbell Gas
Engine Co., Engineers, Halifax ; the Midland Gas Engine,
made by Messrs. John Taylor & Co., Nottingham ; the Trent
Gas Engine, manufactured by the Trent Gas Engine Co.,
Nottingham ; the Day Gas Engine, constructed by Messrs.
Day & Co., of Bath ; and the Fawcett Engine, constructed by
Messrs. Fawcett, Preston & Co., Liverpool.
The ' Campbell Gas Engine ' follows the cycle of operations
first adopted by Clerk, and described at page 184 of this work.
It has two cylinders, respectively pump and motor, driven from
cranks placed at almost right angles to each other, the pump
crank leading. The pump takes in a charge of gas and air, and
the motor piston overruns a port in the side of the cylinder at
the out-end of its stroke to discharge the exhaust gases. When
the pressure in the motor cylinder has fallen to atmosphere, the
pump forces its charge into the back cover of the motor cylinder
through a check valve, displacing before it the products of com-
bustion through an exhaust port ; the motor piston then returns,
compressing the contents of the cylinder into the compression
space. The charge is then fired and the piston performs its
working stroke. This is the Clerk cycle.
The Campbell engine, however, differs in detail from the
Clerk engine to some extent.
Gas Engines giving an Impulse for Every Revolution 287
A hot tube igniter is used, and a vibrating pendulum governor
has been applied.
The Midland Gas Engine also operates on the Clerk cycle.
An ignition tube is used, and governing is performed by centri-
fugal governor.
The Trent Gas Engine is the invention of Mr. Richard Simon
of Nottingham, and in it a trunk piston of two diameters is
caused to perform the combined operations of working and
pump pistons. Fig. no is a vertical section through the com-
bustion or compression space, which in this engine is separate
from the cylinder proper.
FIG. 108. — Trent Gas Engine (vertical section of cylinder).
Fig. 1 08 is a vertical section through the cylinder ; fig. 109 is
a horizontal section also through the cylinder, showing cylinder
and combustion space with the piston removed ; and fig. no is a
vertical section through the combustion space. The cylinder
has two diameters A and c, and in it fits a trunk piston B D ;
the smaller diameter B forms the motor or working piston, and
the larger diameter D forms the pump piston ; the pump cylinder
being formed by the annulus around the trunk piston B. Both
pistons B and D are thus operated together from a crank shaft by
means of one connecting rod. M is the explosion chamber, and
there are three main valves ; E the inlet valve to the pump ; o the
288
The Gas Engine
discharge valve from the pump to the compression space M ; and
R the exhaust valve, s is the timing valve opening to the hot
FIG. 109 — Trent Gas Engine (horizontal section of cylinder).
FIG. no. — Trent Gas Engine (vertical section through combustion space).
tube. When the piston B D makes its out-stroke, gas and air
mixture is drawn into the annular space surrounding the trunk
Gas Engines giving an Impulse for Every Revolution 289
piston B through the charge inlet valve E. On the in- stroke (the
valve being closed mechanically) the mixture of gas and air is
forced from the pump cylinder through the valve o, also operated
mechanically into the combustion chamber M, and partly into the
cylinder A, where it assists to displace the exhaust gases from the
cylinder through the exhaust valve R. The horizontal rib or par-
tition H prevents the direct flow of the entering charge to the
exhaust valve R. At a certain point of the return stroke, so
arranged as to prevent or minimise loss of charge by way of the
exhaust valve R with the exhaust gases, the exhaust valve is closed
and the pump piston continues to force mixture into the space M
while the piston B compresses the charge in the cylinder ; both
pistons B D thus compress the charge, and at the in-end of the
stroke, just after the valve o has been closed, the valve s is
opened and the compressed charge is fired. The piston is forced
out under the resulting pressure ; the return stroke is performed
by the energy of the fly wheel.
Diagrams and Gas Consumption.— From tests published by
the Trent Gas Engine Co. as made by Mr. F. L. Guilford, of
Messrs. G. R. Cowen & Co., Engineers, Nottingham, it appears
FIG. in. — Trent Gas Engine (diagram from power cylinder).
that an engine rated at 4 HP nominal gave 10-2 IHP at 174
revolutions, but the brake HP was only 6 '4 horse. The gas
consumption was 180 ft. per hour.
The enormous difference between the brake power and the
indicated appears to the author to point to an omission on the
part of the experimenter ; the mechanical efficiency could not
have been so low as 63 per cent. ; the pump diagram cannot have
been deducted from the motor diagram.
U
290 The Gas Engine
Fig. in is a diagram taken from the power cylinder of a
4 HP engine ; it shows a compression pressure of 36 Ibs. per
square inch above atmosphere, with a maximum pressure after
ignition of only 84 Ibs. above atmosphere. The gases are ex-
panded down to about 15 Ibs. per square inch before discharge.
This diagram proves conclusively that a large proportion of
exhaust gases remained in the engine cylinder unexpelled. The
rapidity of the ignition also shows that the combustion space M
was filled with rich mixture.
The average available pressure cannot be obtained from this
diagram in the absence of the pump diagram.
General Remarks. — This type of engine has very grave dis-
advantages, low average available pressure, large cooling surfaces,
large volumes of exhaust products remaining in the charge, and
consequent liability to back ignition if any attempt is made to use
high compression ; from these difficulties it follows that no great
economy in gas consumption can be obtained.
The engine was manufactured for some years, but in 1894 the
Company ceased business, and the engine does not now appear to
be manufactured.
i
The Day Gas Engine. — This engine uses the same cycle of
operations for charging the working cylinder as was adopted in
the Tangye-Robson gas engine, and also in the Stockport engine,
described in pages 195 and 197 of this work, but the inventor in-
geniously dispenses with all valves and valve gear such as cams or
eccentrics.
The engine in one form may be described as valveless, and its
only moving parts are, piston, connecting rod and crank shaft ;
there is absolutely no valve used except a governor valve. Fig.
112 is a sectional elevation of one form of the engine, which is of
the vertical inverted cylinder class, having the power cylinder A
overhead.
The piston B operates the crank shaft D by means of the piston
rod c. The crank shaft operates in a closed chamber E, which
chamber serves as a reservoir for gas and air mixture. Three
ports are arranged in the side of the cylinder respectively, F, G, H ;
Gas Engines giving an Impulse for Every Revolution 291
F is the charge inlet port admitting the charge to the cylinder, G
is the exhaust port allowing the discharge of the exhaust gases
from the cylinder, and H is the air inlet port to permit of the
admission of air from the external atmosphere. The charge inlet
port F communicates with the charge chamber E, and opens to the
FIG. 112. — Day Gas Engine (vertical section).
cylinder A opposed by the lip or projection i on the piston B. The
exhaust port G connects by the pipe G1 to the exhaust chamber
G2 of usual construction, and the chamber G2 discharges to the
atmosphere by the pipe G3. The air inlet port H connects by
pipe H1 to the base of the engine K, so as to quieten the air inlet.
The action is as follows. On the up- stroke of the piston B the
u 2
292 The Gas Engine
pressure of the gases in the chamber E is reduced to about 3 or
4 Ibs. below atmosphere ; at or near the end of the up-stroke the
lower edge of the piston uncovers the air inlet port H, and air
rushes into the chamber to bring the pressure up to atmosphere ;
gas is also admitted from the separate governor valve referred to,
so that the chamber E becomes charged with a mixture of gas and
air. On the down-stroke of the piston B the contents of the
chamber E are compressed to 3 or 4 Ibs. above atmosphere, and at
the termination of the down-stroke the port F is uncovered as
shown in fig. 112. The exhaust port G has been crossed by the
piston B somewhat earlier in the down-stroke, sufficiently early to
allow the hot gases from the previous explosion to discharge to
atmospheric pressure before the port F is opened. The charge
then flows from the port F under slight pressure, strikes against
the lip or baffle plate or projection i, and is deflected as shown by
the arrows so that it flows
in a stream to the end of
the cylinder, then turns and
fills the cylinder, expelling
the exhaust gases by the
port F. The piston B then
returns on its up stroke, and
FIG. 113.— Day Gas Engine (diagram). compresses the charge into
a space at the end of the
cylinder to a pressure of about 50 Ibs. per square inch above
atmosphere. The hot tube L then ignites the compressed charge,
timing the explosion by the position of the incandescent part in
a manner which will be explained more fully later on. The piston
then makes its downward stroke under the pressure of the ex-
plosion. By these operations an impulse is obtained at every
revolution, as in the Clerk, Robson, and Stockport engines.
Loss of power is caused by the absence of an inlet suction
valve to the space E, and in later engines a suction valve is provided.
This Day engine has the peculiarity, that it can be run in
either direction; this is possible because of the absence of timing
valves or valve gear operated from the crank shaft.
Diagrams and Gas Consumption, — Fig. 113 is an indicator
Gas Engines giving an Impulse for Every Revolution 293
diagram from this type of engine rated at i HP nominal. The
diagram shows an indicated power of 3-3 horse at 180 revolu-
tions per minute ; the cylinder is 4-5 ins. diameter and 7^ ins.
stroke. The author has not obtained the gas consumption, but
this seems no good reason why the results should be better than
those obtained with Tangyes' Robson gas engine. That engine
gave for the small powers a gas consumption of 40 cubic feet per
brake HP with an average available pressure of about 45 Ibs. per
square inch. The diagram given shows an average pressure of
about 45 Ibs. per square inch, and is probably lower, as allowance
should be made for the work of charging.
General Remarks.— This engine appears to be the only remain-
ing impulse-every-revolution engine now in the market in this
country, and Messrs. Day & Co. are to be congratulated on their
courage in adhering to the impulse-every-revolution type, and
withstanding the temptation to desert and join the makers of Otto
cycle engines.
The author wishes Messrs. Day & Co. every success, but he is
of opinion that further modification is required if results are to be
obtained superior to the older Clerk, Robson, and Stockport
engines.
The Fawcett Gas Engine was manufactured by Messrs.
Fawcett, Preston & Co., of Liverpool, and gave very fair results ;
it does not now, however, occupy any prominent position in the
market. It is the invention of Mr. Beechy, and like the Clerk,
Robson, and Stockport engines, it gives an explosion impulse at
every revolution of the crank shaft.
Fig. 114 is a sectional elevation of the engine ; fig. 115 is a
sectional plan of explosion chamber and valves.
The motor cylinder A is horizontal, and under it is arranged
the pump cylinder B inclined towards the crank centre. The
motor piston A1 connects to the crank pin c by the connecting
rod D, and the pump piston B1 connects to a pin carried by the
connecting rod D by the lower connecting rod E. -The effect so far
as the movement of the piston B1 is concerned is practically the
same as if the rod E were also connected to the crank pin c. The
294
The Gas Engine
piston B1 thus reaches the in-end of its stroke a little before the
piston A1, when the engine rotates in the direction of the arrow
shown in fig. 114. The piston valve F, fig. 115, is operated from
the crank shaft by an eccentric, and it serves to control the
admission of gas and air to the pump cylinder B, and the dis-
charge from the said cylinder to the motor cylinder A ; it also
controls the admission of the compressed charge to the igniting
tube K. A conical seat valve G, shown in dotted lines at fig. 114,
controls the exhaust port H placed about the middle of the
FIG. 114. — Fawcett Gas Engine (vertical section).
cylinder, and the valve is actuated by a bell-crank lever i from a
cam or eccentric on the crank shaft. The action is as follows :
The piston valve F uncovers the port L leading by the passage L1
to the pump cylinder, the pump piston B1 then moves forward
drawing in a charge of gas and air, air by way of the pipe M, and
gas by way of the annular port N, and the perforations or holes N1.
When the pump piston has completed its outstroke the piston
valve F closes the port L, and opens by way of the annular space
between the two piston ends of the valve to the port o, which
port communicates with the combustion space A2 and cylinder A.
Gas Engines giving an Impulse for Every Revolution 295
The piston A1 is then on its instroke, together with the piston B^
and the exhaust valve G is held open so that the exhaust gases
discharge into the atmosphere, and some of the charge enters
from the pump and assists to displace them. When the piston A1
has crossed the exhaust port H, the greater part of the burned
gases have been discharged, and part of the pump charge has
'W
FIG. 115. — Fawcett Gas Engine (sectional plan of combustion chamber).
been forced from the cylinder B through the passage L1 port L, and
port o into the space A2 ; the continued movement of the piston
forces a further part of the charge into the working cylinder while
compression is being caused by both pistons. When the piston B1
arrives at the \n-end of its stroke the piston valve moves to close
the port L, as shown in fig. 115, and the piston A1 further com-
presses the charge. The continued movement of the piston
valve F opens the incandescent tube K, and ignition takes place,
296 The Gas Engine
driving the piston A1 on its working stroke. The charge is ex-
panded to the end of the stroke, and the exhaust valve is opened
for the return. By this arrangement an impulse is secured at every
revolution of the engine.
Diagrams and Gas Consumption. — Experiments on the engine
were made by Mr. T. L. Miller in 1890, from which it appears
that in an engine indicating ii'49 HP at 150-8 revolutions per
minute, 8-52 BHP was obtained with a gas consumption of
1 8-4 cb. ft. per IHP per hour and 2474 cb. ft. per BHP per
hour. The test was made with Liverpool gas, which evolves
399-6 Ibs. Centigrade heat units per cb. ft. at 17° C, or heat
equivalent to 555,490 ft. Ibs. per cb. ft. If all the heat of the gas
could be converted into mechanical work 3*564 cb. ft. would
give i IHP for an hour. The absolute indicated efficiency of the
3-564 x 100
engine is therefore g. =I9'3 per cent.
General Remarks. — This engine closely resembles the Clerk
type of engine in the arrangement of pump and motor piston,
but it is subject to considerable difficulties in securing the dis-
charge of the burned gases without simultaneously losing un-
burned mixture of gas and air. The principal difficulty of all
engines having open exhaust ports at the time of charging the
cylinder lies in the proportioning and directing the flow of the
entering gas and air to displace the burned gases without passing
unburned gas away through this exhaust port. In the Clerk engine
this trouble was met by the long conical entrance and considerable
length of cylinder for the sweep of the entering gases ; and in all
engines such as the ' Trent ' and the ' Fawcett,' where the power
piston is discharging gases simultaneously with the entrance of the
fresh charge, this trouble is increased, and it becomes necessary to
leave large volumes of exhaust gases in the cylinder to avoid loss
of gas at the exhaust ports. Mr. Beech ey has succeeded very well
indeed in minimising loss from this cause, as shown by the very
fair results he obtains. He has the advantage of greater expan-
sion than the * Otto ' type, although the disadvantage of greater
proportion of exhaust gas brings down his economy.
297
CHAPTER II.
OTTO CYCLE GAS ENGINES.
THE ' Otto cycle engines are those which possess at present a
living practical interest, and great advances have been made in
them since 1886 ; in particular the gas consumption has been much
reduced. The power of the engines constructed has also been
greatly increased. In 1886 a nine-horse (nominal) gas engine of
Messrs. Crossley's construction consumed about 2 7 cb. ft. of Man-
chester gas per brake horse power per hour, and now (1895) a
similar engine consumes as little as 17 cb. ft. per brake horse
power. The increase in power is also striking ; engines of 40 HP
were the largest made in 1886, but now Otto cycle engines are
built as large as 400 I HP. It is interesting to trace the steps
which have made such improvement possible, and this will be best
done by the study of the drawings of Otto cycle engines of recent
construction. As the Messrs. Crossley are still the leading con-
structors of gas engines in the world, turning out from their shops
about sixty engines every week, the author will first consider one of
their engines.
Crossley Otto Engine. — Careful drawings have been made of a
Crossley Otto engine of 9 HP (nominal) built in 1892, and now at
work at the Clifton Rocks Railway, Bristol. The engine is num-
bered 19772. It has been thought best to select an actual engine
as an example in order to clearly appreciate the points of difference
from the earlier engines. The particular engine selected was
tested by the author for power and gas consumption. The engine
shows many points of advance over the 1886 engines, but curiously
enough, although it possesses all the necessary valve arrangements
to enable high compression pressures to be utilised, yet defects
in the proportion of the compression space and piston prevented
298
The Gas Engine
the use of high compression, and the engine did not give the best
economy possible for the particular type. Accordingly the gas
consumed per brake HP hour was 25-9 cb. ft. This is a much
better result than would have been obtained from a slide valve
Otto Cycle Gas Engines
299
Otto engine such as illustrated on pages 167, 169 and 171 of this
work, but it is not nearly so good as the type allows.
Fig. 116 is a side elevation of the engine ; fig. 117 is a plan
part in section; fig. 118 an end elevation; figs. 119-123 inclusive
300
The Gas Engine
are drawn to a larger scale; fig. 119 is a side elevation of the back
end of the cylinder looking on the cam shaft; fig. 120 is a corre-
sponding plan; fig. 121 an end elevation; fig. 122 a vertical longi-
tudinal section through the cylinder, and fig. 123 is a separate
section on a still larger scale of the igniter tube and funnel.
A comparison of the illustrations with those of the earlier slide
valve engine at once shows great mechanical development and
points of constructive difference. Thus in the early engine the
crosshead guide and the engine cylinder were two distinct parts
requiring to be bolted together in accurate alignment in order to
allow the piston with its cross-
head slide to work freely without
jamming : in the later engine a long
trunk piston is used which serves
the double purpose of piston and
crosshead guide ; the separate
crosshead slide is, in fact, dis-
pensed with, and consequently the
cylinder serves as its own slide
guide, requiring no adjustment of
separate parts. The cylinder, that
is, serves both as cylinder and
slide guide, and the whole cylinder
is bolted to the bed against a
powerful faced flange.
The bevil wheels of the early
design are also dispensed with
IF*
FIG. 118.— Crossley Otto Engine,
9 PIP Nominal (end elevation).
and replaced by skew or worm wheels, which besides taking up
much less space provide a much quieter drive for the two to one
shaft. The unsightly distortion of the bed shown in fig. 51 neces-
sary to admit the bevil wheels is quite avoided, as is clearly seen
at fig. 117. There are many smaller points of constructive dif-
ference which the experience of years has shown to be desirable,
but the great points of departure are to be found in— the suppres-
sion of the flame slide valve method of ignition, and the introduc-
tion of the incandescent tube igniter; the diminution of the
relative volume of the compression space, which is not carried out
to its proper extent in this individual engine ; and the improved
Otto Cycle Gas Engines
301
proportioning of the valves and ports in order to minimise the
throttling of the charge during the inlet period and the back
pressure of the exhaust gases during discharge.
The engine follows the same cycle of operations as the old
engine; that is, by one movement of the piston it takes into the
cylinder a charge of gas and air which is compressed on the return
stroke into a space at the end of the cylinder, there to be ignited
in order to give the explosion and produce the power stroke ; the
power stroke is then followed by the exhausting stroke, and the
FIG. 119. — Crossley Otto Engine, 9 HP Nominal (side elevation, back end).
engine is ready to go through the same operations to prepare for
another power stroke. In this engine the charge of gas and air is
admitted by the inlet valve i, which is of the conical seated lift type ;
the valve is operated by the lever j from a cam K on the valve shaft D.
This valve shaft is rotated at half the speed of the crank shaft by
means of worm wheels or skew gear E. The gas supply is admitted
to the inlet valve i by the lift valve L, which valve is also operated by
the lever and link N and cam M, controlled, however, by the centri-
fugal governor s. The governor operates to either admit gas wholly
or cut it off completely, so that the variation in power is obtained
302
The Gas Engine
by varying the number of the explosions. The exhaust valve F is
also a conical seated lift valve, and it is actuated by the lever c
and cam H. The ignition is produced by admitting a portion of
the compressed inflammable charge from the compression space to
the tube R, rendered incandescent by the Bunsen flame. The
^/
WORKING ICMIT»ONO»n| I I f--tr- rf
ST/M»TIN<; IC.N4TION CAfy 1 " L— I
I FT
FIG. 120. — Crossley Otto Engine, 9 HP Nominal (plan, back end).
passage to the igniter tube is controlled by the valve o, which
valve is operated by the lever Q and cam p. The valve o is double
seated, and during the compression period of the engine the face
nearest the compression space is kept up against the seat by a
powerful spring ; the incandescent tube is thus kept open to the
Otto Cycle Gas Engines
303
atmosphere, and notwithstanding any leak which may occur from
the cylinder the tube remains empty until the moment when it is
required for ignition. When the valve is lifted from one seat a
small portion of the compressed mixture is discharged through a
small port to the air, and this clears out the burned gases,
which would otherwise render ignition irregular, and permits pure
FIG. 121. — Crossley Otto Engine, 9 HP Nominal (end elevation).
combustible mixture to reach the incandescent internal surface of
the tube when the outer valve face closes on its seat. This device
causes the ignition of the explosive mixture at the proper time.
The adoption of lift valves for the admission and discharge
of gases to and from the engine cylinder simplifies the
practical problem of admitting and discharging with the least
possible throttling or wire drawing. So long as slide valves were
304
The Gas Engine
used to admit the charge to the cylinder, it was difficult to provide
a sufficiently large inlet area, as the area allowed in a port bearing
against a slide surface determined the pressure necessary to hold
the slide against the valve face to prevent the escape of flame
i
'I
W
o
O
when the compressed mixture was exploded. IB a six horse-
power engine of the old type, for example, the inlet port in the
back cover was 2§ inches long by f inch wide, equal to i -5 square
inches. Assume the maximum pressure of the explosion to be
Otto Cycle Gas Engines
305
150 Ibs. per square inch, then the slide valve must be pressed to its
working face with a pressure not less than 225 Ibs. ; as a matter of
fact the slide was pressed up to its work with a pressure of about
600 Ibs. When it is considered that the flame temperature
during the explosion is about 1600° C. it is easy to comprehend
the difficulty of keeping the slide cool enough to maintain a good
working surface even at comparatively low pressures. Designers
of slide engines for this reason were forced to content themselves
both with the minimum of port area and with low compressions.
Small port area produced naturally considerable resistance to the
inflowing charge, and low compressions prevented the attainment
of any great economy of gas
consumption. In the old
engines, the velocity of flow
of the air and gases entering
the cylinder often exceeded
244 feet per second, so that
when the piston reached the
out end of its stroke the
cylinder was not filled up to
atmospheric pressure. The
evil of throttling in this way
was not confined to the
active loss of power due to
the resistance to the charg-
ing stroke of the piston ; the
greatest loss was caused by
IF'
j
FIG. 123. — Crossley Otto Engine,
9 HP Nominal (section of tube igniter).
the considerable reduction in the weight of the charge drawn in,
and the consequent increase in the proportion of the exhaust gas
present. In many cases it was found that the contents of the
cylinder were at a pressure of i^ Ib. per square inch below atmo-
sphere when the engine terminated its charging stroke, and this
meant that the total volume of charge admitted was reduced by 20
per cent, as compared with the charge which would have entered
had the admission area been sufficient to allow the cylinder to fill
up to atmospheric pressure. The proportion is greater because of
the large volume of the compression space which must be
allowed for in calculating the loss due to deficit of pressure. The
306 The Gas Engine
slide valve was undoubtedly a formidable difficulty in these
engines, now happily overcome by the substitution of lift valves.
With lift valves it is easy to provide any desired admission port
area,, as the pressure of the explosion holds the valve to its seat,
and large valves may be used just as readily as small ones. In
the engine illustrated in figs. 116-123 the admission area is 6-52
square inches, with the valve full open, and assuming maximum
opening to remain during the whole charging stroke the velocity
of the entering charge is only 87 feet per second. This engine
is therefore better supplied with combustible mixture than the old
slide engine.
The compression pressure in a slide valve engine is limited by
the difficulty of preventing a slide from cutting on its face at high
compression and explosion pressures, and this difficulty is also
overcome by the use of lift valves when combined with an
incandescent tube igniter.
In the older engines the importance of a free exhaust exit was
not fully recognised, and although the exhaust valves were lift
valves, the discharge area provided was insufficient. Thus in the
six-horse slide valve engine referred to, the average velocity of the
exhaust gases past the exhaust valves was 137 feet per second ;
in the present engine it is only 48 feet per second. The exhaust
gases are thus better discharged in the recent engine. Any
increase in the volume of the exhaust products causes loss of
economy in a gas engine ; a small proportion does little harm,
but a large volume of exhaust heats the entering charge and so
raises the temperature of compression. Premature ignitions
are also caused by the compression of a charge mixed with hot
exhaust. Designers now endeavour to expel exhaust products
as completely as possible.
The engine illustrated has several bad points, and it appears
to the author to be one issued by the makers while they were in a
transition stage, probably engaged in increasing their compression
pressures. To get the best possible results from a given volume
of explosive mixture, it should be compressed into a combustion
space, having the minimum of port capacity communicating with
the admission and exhaust valves. In the older engines this
point was not appreciated, and the port capacity was always
Otto Cycle Gas Engines 307
excessive. In this engine the port capacity back to the exhaust
and inlet valves is undoubtedly too great. Ports act as con-
densers for the flame of the explosion, and rapidly cool the ignited
charge at a time when it least bears cooling. Any narrow spaces
should also be avoided, and this engine presents an example of
attempting to increase compression, by means of the block v
attached to the piston, which should be carefully avoided It will
be noticed that the block v, fig. 117, projects into the combustion
space through the reduced diameter part x, and so forms the
annular space Y between the piston proper and the reduced
casing. This annulus has a cooling effect on the flame under the
explosion pressure while the piston A is practically stationary, but
it has a much more serious cooling effect whenever the piston
begins to move out. The flame gases then pass through the space
between the piston block v and the ring x into the annulus Y,
and so the flame is dragged through a cooling or condensing
surface, and considerable loss is thus caused. Indeed it may be
at once stated, that to gain the greatest advantage from high com-
pressions the whole of the compressed explosive mixture should
be contained in one space, that is a space which is not divided
into smaller separate spaces. Ports should be avoided if possible,
and the flame should never be caused to flow through a narrow
space into a wider one, as is done in this engine. The compres-
sion space should in fact be as nearly cubical or spherical as
possible. Notwithstanding these defects, the engine shown in the
illustration gives much better results than the old slide valve
engines. For the purpose of comparison the author made prac-
tically simultaneous tests on the engine illustrated and on an
old slide valve engine of six horse power (nominal). The results
obtained are given in the table on page 310, and all the important
valve settings and numbers are also given.
Fig. 1 24 is a diagram from the engine illustrated. It is a fair
example of those taken during the test.
Fig. 125 is the corresponding light spring diagram.
Fig. 126 is a diagram from the slide valve engine which has
been referred to, and fig. 127 is a light spring diagram also from
the slide valve engine.
The scales of the diagram figs. 124 and 126 are different, as
x 2
308
The Gas Engine
one required a much stronger indicator spring. It will be ob-
served that the slide valve engine only gives an available working
pressure of 54*8 Ibs. per square inch, while the lift valve engine
250
Nominal HP, 9 ; diam. of cylinder, g\" ; length of stroke, 18" ; revs, per min.
160 ; indicated HP, 19*25 ; consumpt. per 1HP per hour, 21 '2 cb. ft. ; consumpt.
loose, 70 cb. ft. per hour ; brake HP, 15*75 : consumpt. per BHP per hour, 25*9
cb. ft. ; mean pressure, 81*5 Ibs. ; max. pressure, 200 Ibs. ; pressure before ignition,
46 Ibs. ; scale of spring, T^5" per Ib.
FIG. 124.— Crossley Otto Engine, 9 HP Nominal (diagram).
gives 81-5 Ibs. ; and on comparing the light spring diagrams it will
be seen that with the slide valve engine the pressure falls consider-
r-,25
20
UJ
J
<h
O
15
10
Scale of spring, ^" per Ib. ; mean pressure, 2*5 Ibs. ; charging resistance, 0*7 I HP ;
total resistance running loose, 3*3 IHP.
FIG. 125. —Crossley Otto Engine, 9 HP Nominal (light spring diagram).
ably below atmosphere at the end of the charging stroke, while
with the other engine the pressure rises nearly to atmosphere
before the stroke terminates.
Otto Cycle Gas Engines
309
Cross ley Otto ' Scavenging' Engine. — The Crossley Otto engines
now built differ to a considerable extent from the engine No.
120
100
Nominal HP, 6 ; diam. of cylinder, 8" ; length of stroke, 16" ; rev. per min. 164 ;
indicated HP, 9 ; consumpt. per IHP per hour, 25-5 cb. ft. ; brake HP, 675 ; con-
sumpt. per BHP per hour, 34 cb. ft. ; mean pressure, 54'8 Ibs. ; max. pressure,
125 Ibs. ; pressure before ignition, 32 Ibs. ; scale of spring, ^" per Ib.
FIG. 126. -Crossley Otto Engine, 6 HP slide valve (diagram).
19772 which has been here discussed. Figs. 128 and I28A show
the external appearance of the. present engines. Fig. 128 shows
the 30 HP nominal engine of 17 in. cylinder and 24 in. stroke,
5
•7 IHP ;
Scale of spring, Ty per Ib. ; mean pressure, 3*85 ; charging resistance, 0*7
total resistance running loose, 2*25 IHP.
FIG. 127. — Crossley Otto Engine, 6 HP slide valve (light spring diagram).
intended for ordinary driving and running at 160 revolutions per
min. Fig. I28A is the 30 HP nominal electric lighting engine of
3io
The Gas Engine
PRINCIPAL PARTICULARS
OF A 6 NHP CROSSLEY OTTO GAS ENGINE, BUILT ABOUT 1881,
AND A 9 NHP CROSSLEY OTTO GAS ENGINE, No. 19772, BUILT IN 1892.
6 NHP Engine, No 4683
6" diam. cylinder x 16" stroke
9 NHP Engine, No. 19772
9^" diam. cylinder x 18" stroke
Volume swept by piston
804 cub. ins.
1275 '8 cub. ins.
Volume of compression space.
516 cub. ins.
510 cub. ins.
Vol. swept by piston
804 i
1275-8 i
Vol. of comp. space ' *
516 0-64
510 0-4
Compression pressure . .
j 31 Ibs. per sq. in. above
1 atmos.
48 Ibs. per sq. in. above
atmos.
Explosion pressure .
(125 Ibs. per sq. in. above
( atmos.
200 Ibs. per sq. in. above
atmos.
Mean available pressure
57 Ibs. per sq. in.
Si's Ibs. per sq. in.
Revolutions per minute .
164
160
Indicated horse power .
Q'o
J9°25
Brake horse power .
6'75
i5'75
Gas consumption per hour
(including ignition)
236 cub. ft.
408 cub. ft.
Gas per I HP per hour .
25 '5 cub. ft.
21 '2 Cub. ft.
Gas per BHP per hour .
Mechanical efficiency . • .
34 cub. ft.
75 per cent.
25*9 cub. ft.
81 per cent.
, Area of charge inlet port
(Slide valve) 1*5 sq. in.
(Inlet valve 2§ " diam. x £"
lift) 6*52 sq. ins.
\
Opens dead on in centre, is
Is \" open when piston is
held open on out centre,
Inlet port setting .
on in centre, and J" open 1
when, piston is on out
and closes when the piston
returns ii" in. At i" in
centre
movement" of piston the
Exhaust valve
i valve is •£,." open
f(aj" diam. x f" lift) 2-65 (3" diam.xij" lift) n'78
sq. in. area sq. in. area
/ Opens while piston is i"
1 in from out end of stroke.
Opens while piston is 2!"
Exhaust valve setting .
4 Closes when piston has from out end of stroke.
crossed in centre and
Closes exactly on in centre.
\ moved out J"
(Lift valve tube igniter)
Ignition lead ....
Ignition port in slide is an
- i" open when crank is on Y
valve y>" diam. x -fs" lift,
opens T.\" before compres-
sion is complete, but only
in centre
full open i" before com-
pression is complete
Charge velocity
244 ft. per sec.
87 ft. per sec.
Exhaust velocity
Piston speed .
137 ft. per sec.
437 ft. per min.
48 ft. per sec.
480 ft. per min.
Power absorbed charging and
exhausting .
j- 0-7 IHP
0-7 IHP
Gas inlet valve
|" diam. x tf" lift
i" diam. x§" lift
I\
When piston has gone z\"
Gas inlet valve setting .
When piston has made i \"
forward stroke valve -
forward stroke valve opens,
and does not close till out
centre has been crossed and
opens
piston returns ii". Valve
i is "M?" open when piston is
/ I full out
17 in. diam. cylinder and 21 in. stroke, which runs at 230 revolu-
tions per min., and with coal gas will indicate a maximum power
of 1 1 7 horse. The engines now supplied are of the ' scavenging *
312
The Gas Engine
type. The general external appearance is similar to that illus-
trated, but an important modification is made in the operations
performed by the engine. In addition to the cycle of operations
described, the engine is so arranged that the exhaust gases
formerly remaining in the combustion space are swept out and
the combustion space filled with air. The combustible charge in
this engine is therefore a pure mixture of gas and air without any
Otto Cycle Gas Engines
313
exhaust gases. To accomplish this clearing out of the burned
gases and their replacement by air, advantage is taken of the
oscillations or waves of pressure set up in the exhaust pipe by
the discharge of the exhaust gases. It has long been known that
in a gas engine exhaust pipe the pressure of discharge is suc-
ceeded by a partial vacuum, and this vacuum again succeeded
FIG. 129.
FlG. 129. — Crossley Otto Scavenging Engine (vertical section of cylinder).
FlG. 130. — Do. (sectional plan of cylinder).
by pressure, in fact that under certain circumstances an oscilla-
tion of pressure is set up in the exhaust pipe, giving a fall of
pressure at certain periods after the exhaust valve is opened.
Messrs. Crossley & Atkinson take advantage of this fact, and
so control the pressure wave and the following vacuum that after
the exhaust gases have been liberated from the cylinder of the
The Gas Engine
engine the high-pressure discharge is succeeded by a vacuum,
the period of the vacuum coinciding with the approach of
the piston to the end of its exhaust stroke. By then keeping
open the exhaust valve and opening the charge or an inlet valve
while the exhaust valve is open, a charge of pure air is drawn
FIG. 131.
FIG. 131.— Crossley Otto Scavenging Engine (end elevation).
FIG. 132.— Do. (transverse section).
through the combustion space to sweep out the burned gases from
the compression space. When the charging stroke is complete
the whole cylinder is thus filled with a pure mixture of gas and
air without the deleterious burned gases. To accomplish this
sweeping out in a satisfactory manner it is necessary to shape the
cylinder so as to favour the free flow of the entering air.
Otto Cycle Gas Engines
315
Figs. 129, 130, 131, 132 are, respectively, vertical section; sec-
lional plan ; end elevation ; and transverse section illustrating the
arrangement of a 4 HP nominal engine tested by the author at
Messrs. Crossley's works in Manchester.
Fig. 133 illustrates in a diagrammatic way the settings of the
valves in that engine.
The desired delay in the production of the vacuum is brought
about by attaching an exhaust pipe c of about 65 ft. long. Quiet-
ing chambers may be placed at the end of that length of pipe
without affecting the result, but no large expansion or chamber
should be put nearer to the engine cylinder. The energy of dis-
charge of the exhaust sets the long column of gases filling the
pipe in oscillating motion, and enables a considerable reduction of
pressure to be produced just as the piston is completing its ex-
FIG. 133. — Crossley Otto Scavenging Engine (valve settings).
haustinf; stroke. Fig. 134 is a light spring diagram taken from the
engine during the author's test, and it plainly shows the effect of
the vacuum so produced in the exhaust pipe. It will be noted
that at the termination of the exhausting stroke the pressure in
the cylinder has fallen to 2 Ibs. per square inch below atmosphere,
a reduction of pressure amply sufficient to cause a flow of air from
the atmosphere sweeping through the cylinder.
On figs. 130 to 132 the arrows show the direction of the air
current passing in by the inlet valve A through the specially shaped
cylinder and out at the exhaust valve B.
In fig. 133 the air inlet valve is opened while the crank is in
the position D, and the exhaust valve is held open till the crank
reaches the position B. The exhaust valve opens again at A, and
it is held open to B position instead of as usual to c position. The
316
The Gas Engine
inlet valve is thus held open during the existence of a partial vacuum
in the exhaust pipe, and so a ' scavenging ' charge of air is drawn
FIG.
through
air.
Fig.
Scale of spring, ^" per Ib. ; charging and scavenging diagram ;
charging diagram of 4 NHP Crossley Otto Engine.
134.— Crossley Otto Scavenging Engine (light spring diagram),
the combustion space and the products replaced by pure
135 is a diagram taken by the author during his test of the
Nominal HP, 4 ; diam. of cylinder, 7"; length of stroke, 15" ; rev. per min. 200;
indicated HP, 14 ; consumpt. per IHP per hour, 14*5 cb. ft. ; brake HP, n'97J
consumpt. per BHP per hour, ij'o cb. ft. ; mean pressure, 100*9 ^5. > m'*x-
pressure, 274 Ibs. ; pressure before ignition, 87 Ibs. ; spring, Tf „".
FIG. 135. — Crossley Otto Scavenging Engine (power diagram).
scavenging engine at Messrs. Crossley's works, Openshaw. The
leading particulars are marked upon the diagram, from which it
will be observed that the engine gave results which were most
Otto Cycle Gas Engines
317
remarkable both from the points of power and economy. The
engine, although only 7 in. diam. cylinder and 1 5 in. stroke, gave
practically 12 -brake horse power on a gas consumption of 17 cb. ft.
per brake horse power hour, a surprisingly good result for so small
an engine. Openshaw gas is 20 candle power, and has a heat
value of 53,000 ft. Ibs. per cb. ft.
Diagrams and Gas Consumption. — The diagrams given at figs.
124, 125, 126, 127, 134 and 135 illustrate very fairly the progress
made in the Crossley Otto engine from the old slide valve engine
to the present lift valve scavenging engine, and it is interesting to
compare the consumption of these three engines. They are as
follows :
Gas
per I HP hour
Gas
per B HP hour
Compression
pressure per sq.
in. above atmos.
Slide valve engine
Lift valve engine, No. 19772
Lift valve scavenging engine
25-5 cb. ft.
21 "2 Cb. ft.
14*5 cb. ft.
.34 cb. ft.
25-9 cb. ft.
17 cb. ft.
30 Ibs.
46 Ibs.
87 -5 Ibs.
The advance made by the Messrs. Crossley is quite unmis-
takable ; the brake consumption is now just about half of the
consumption in a Crossley Otto engine built in 1881. No doubt
many of their slide valve engines were more economical than the
one tested by the author, and the gas consumption of engine
No. 19772 does not represent the most favourable result attained
by the Messrs. Crossley before the advent of the scavenging engine.
Thus the Crossley engine tested at the Society of Arts trials at the
•end of 1888 had a cylinder of 9-5 ins. diameter and a stroke of
1 8 ins. The gas consumed per indicated horse power per hour
was 20-55 cb. ft. and per brake horse power 23-87 cb. ft. The
compression pressure was 6r6 Ibs. per sq. in. above atmosphere.
The indicated power was 17*12 horse, brake power 14-74 horse,
and the speed of the engine 160 revs, per minute. The mean
effective pressure was 67-9 Ibs, per sq. in. and the initial pressure
of the explosion 197 Ibs. per sq. in. above atmosphere.
The author's test of the 4 HP Crossley Otto scavenging
engine was made in August 1894, so that, taking the Society of
Arts Crossley engine as the most economical up to that date, from
3 1 8 The Gas Engine
1888 to 1894 the Messrs. Crossley succeeded in reducing the gas
consumption per brake horse power from 24 to 17 cb. ft.
It is to be remembered that this figure of 17 cb. ft. per
brake HP was obtained with a small engine. Mr. Atkinson, of
Messrs. Crossley, has given the author results of a test made with
an engine of n^ in. diam. cylinder and 21 in. stroke also at Man-
chester. The power indicated was 46*8 horse, and the gas con-
sumption was only 13*55 CD- ft- Per IHP hour. The consumption
of 17 cb. ft. per brake HP per hour is the lowest of which the
author has experience with an engine so small. It will be observed
that increasing economy in the Crossley Otto engine has always
been accompanied by an increase of compression; thus a compres-
sion of 30 Ibs. in the slide valve engine of 1881 has been displaced
in 1894 by a compression of 87*5 Ibs.
Compression has evidently some part in securing the advan-
tages of the present engine. Mr. Atkinson, in a paper read before
the Manchester Association of Engineers, attributes the whole of
the economy of the recent engine to the discharge of the burned
gases and their replacement by pure air. In this the author does
not agree with him ; he will, however, reserve the discussion of the
matter to a general chapter upon gas engine economy, and he will
now proceed to give a short account of the Otto engines of other
makers.
The Stockport Otto Engine.— Messrs. J. E. H. Andrew & Co0
of Reddish now build a well-designed and carefully made Otto
engine which they call the ' Stockport Otto.' Figs. 136, 137 and
138 illustrate its principal details. Fig. 136 is a side elevation of
the cylinder and back part of the engine frame showing the back
cover in longitudinal section through the admission valves. Fig. 137
is an end elevation looking on the back cover, partly in section to
show the igniting valve, the charging valve, and the exhaust
valve.
Fig. 138 is a section on a larger scale of the incandescent tube
and the timing and starter valve.
In fig. 136 the gas and air admission valve is shown nearest to the
combustion space, the air to supply it being drawn along a passage
cast outside the cylinder water jacket, from the bed of the engine,
which serves as an air suction silencer. The gas supply valve is shown
Otto Cycle Gas Engines
319
outside the charge admission valve ; it is pressed down to its seat
by a spring above it, and when it is lifted the gas from the gas pipe
FIG. 136. — Stockport Otto Engine (side elevation).
FIG. 137. — Stockport 'Otto Engine (end elevation).
passes directly into the chamber under the charging valve and
•mixes with the air entering the cylinder. The gas valve is operated
320
The Gas Engine
by a lever similar to those shown in fig. 137, but the centrifugal
governor shown in fig. 136 controls the lever by means of an inter-
posing lever shown as connected to the governor sleeve. A
short straight port communicates with the interior of the cylinder
from above the charging valve. In fig. 137 the charging valve is
again seen in section in the middle of the cylinder ; the exhaust
valve is also shown in section at the left-hand side of the drawing ;
both valves are brought to their seats by springs, and are operated
FIG. 138.— Stockport Otto Engine (section incandescent tube and starter).
by levers from the side shaft. • In fig. 137 is also shown a section
of the igniter tube and its timing valve. The timing valve opens
into the port above the admission valve, and it is controlled by a
lever and cam shown. From fig. 137 it will be seen that the exhaust
valve is also connected to the cylinder by a short straight port.
The section of igniter tube and starting valve, fig. 138, shows an
incandescent metal igniter tube G, heated in the usual manner,
but having a small internal tube passing into it from the space
Otto Cycle Gas Engines
321
controlled by the timing valve F. The valve A is used for starting,
and will be described later on. The lever D opens the timing
a
Nominal HP, q ; diam. of cylinder, of"; length of stroke, 17" ; rev. per min. 184;
consumpt. per I HP per hour, 19 cb'. ft. ; brake HP, 20*8 ; consumpt. per BHP per
hour, 22*3 cb. ft. ; consumpt. loose, 6-$'6 cb. ft. ; mean pressure, 91*8 Ibs. ; max.
pressure, 230 Ibs. ; pressure before ignition, 60 Ibs. ; scale of spring, Tjy per Ib.
FIG. 139. — Stockport Otto Engine (power diagram, 60 Ibs. compression).
ISO
MP 101 I LBS
Nominal HP, 9 ; diam. of cylinder, 9-5"; length of stroke, 17" ; rev. per min, 182 ;
consumpt. per I HP per hour, £7'6 CD. ft. ; brake HP, 24*4 ; consumpt. per BHP
per hour, 20*75 > consumpt. loose, 72 cb. ft. ; mean pressure, loi'i Ibs. ; max.
pressure, 270 Ibs. ; pressure before ignition, 90 Ibs. ; scale of spring, T^" per Ib.
FIG. 140.— Stockport Otto Engine (power diagram, 90 Ibs. compression).
valve F at the proper moment and admits compressed inflammable
mixture from the port above the admission valve of the engine to
Y
322
The Gas Engine
the tube G by way of the internal tube. The mixture then ignites,
and the explosion is communicated to the cylinder. The chamber
above the valve A serves to cause a sufficient rush through the
tube G to make certain that explosive mixture reaches the incan-
descent surface of the tube ; the valve F is held open long enough
to allow the whole of the contents of the spaces and igniter to
discharge into the exhaust valve so as to be ready for another
explosion.
Diagrams and Gas Consumption. — Mr. A. R. Bellamy of
Messrs. Andrew & Co. has been good enough to send the author
the diagrams, figs. 139 and 140, which have been taken by him
from a Stockport Otto engine of the construction described. The
engine had a cylinder of 9} in. diameter and a stroke of 1 7 in.
The particulars of each test have been marked under the diagram.
Scale of spring, Ty per Ib. ; charging diagram from Engine No. 6242 at 60 Ibs.
compression.
FIG. 141. — Stockport Otto Engine (light spring diagram).
The diagrams are especially interesting, as they are taken from
the same engine, but with a smaller compression space in the one
case than in the other. In the first diagram the compression space
is proportioned to give a compression pressure of 60 Ibs. per square
inch, while in the second the compression is 90 Ibs. per square
inch above atmosphere. The difference in economy is marked, as
with the lower compression the engine consumed 19 cb. ft. per
IHP hour, and with the higher compression only 17*6 cb. ft. per
I HP hour. Fig. 141 is a light spring diagram from the same
engine.
Stockport Otto 400 HP Engine. — Messrs. Andrew & Co. have
built perhaps the largest gas engine in the world, and they have
kindly supplied the author with drawings from which the illustra-
Otto Cycle Gas Engines
323
tions, figs. 142, 146, have been prepared. The principal dimen-
sions and a list of the parts are marked upon the figures. The
arrangement of the engine is novel and interesting ; two cylinders
Y2
324
The Gas Engine
are mounted, tandem fashion, on a bed plate. To avoid passing
a piston rod through a combustion space the pistons are connected
by a system of piston rods, crossheads and side rods ; both pistons
thus connect to one crank shaft by a common connecting rod.
Each cylinder operates on the Otto cycle, but the valves are timed
to make the explosions alternate, and so an impulse is obtained for
every revolution of the fly-wheel.
The engine is applied to actuate a mill at Godalming, and it is
FIG. 144. — Stockport Otto Engine, 400 IHP
(end elevation with valve in section).
supplied with gas generated by a Dowson plant. The maximum
indicated power is stated to be 400 horse. The author has not as
yet obtained indicator diagrams from this engine.
Barker's Otto Engine. — In the examples which have been given
of the Crossley and Stockport Otto engines it will be observed that
both charging and exhausting valves communicate with the interior
of the cylinder by ports of considerable dimensions. The ports in
the Stockport engines are smaller than those in the Crossley ;
Otto Cycle Gas Engines
325
other conditions being similar, an engine where the whole of the
mixture is contained in one large space, without small subsidiary
spaces, is less liable to loss of heat at the maximum temperature
of the explosion. It follows from this that if ports and passages
can be avoided, then greater economy will be obtained. It is very
convenient from a constructive point of view to build gas engines
with ports, because it allows the charging and admission valves
to be contained in separate casings, which can be bolted on the
cylinder facings. Such casings also allow of the easy removal
of the valves for cleaning, by merely unscrewing a light cover.
FIG. 145. — Stockport Otto Engine,
400 IHF (longitudinal section through
exhaust valve).
FIG. 146. — Stockport Otto Engine,
400 IHP (longitudinal section through
gas and air valves).
Notwithstanding the great convenience of passages, it is important
to dispense with them.
Messrs. T. B. Barker & Co. of Birmingham have kept this
point well in view in designing their Otto engine, which is illustrated
at figs. 147-149. Fig. 147 is a side elevation of the engine with
part of the cylinder in section to show the valve arrangements.
Fig. 148 is a plan and fig. 149 is an end elevation. Here port
surface has been practically abolished, as the valves are placed so
as to open directly into the cylinder. The exhaust valve i and
the charging valve 2 are carried in separate turned sleeves, which
fit into bored recesses terminating at their inner ends in conical
326
The Gas Engine
valve seats. The sleeves are held up to their respective conical
seats by a bridge piece 3 screwed on by the single nut 4. The
ends of the bridge piece bear upon the ends of the sleeves, and on
screwing up the nut 4 both sleeves are firmly pressed home. The
valves are pulled to their seats by the spring 5 which also acts by
Otto Cycle Gas Engines
327
a bridge or stirrup. The valves are opened by levers 6, one of
which, the admission valve, is here seen in the end elevation, fig. 149.
The levers are operated by cams on the usual two to one shaft,
1 II
•« g"
s
-c.S-
. rt *p( a) u
jjj'x <o o M
« o
43 O .2 bb-S
4-> ^ " X.
WT! Ml?
ol tf|a-
-•^ ^ o c
be ea c °
328
The Gas Engine
By this arrangement the upper surface of the exhaust valve i
forms part of the interior surface of the cylinder, and so far as the
exhaust valve is concerned the prejudicial port surface is abolished.
The charging valve 2 also opens directly into the cylinder, but
here it has been found advisable to allow the charge to enter the
cylinder by way of a recess or cavity 7 ; this recess, however, is very
open, and does not appreciably increase the cooling surface. It
has been found desirable to have a cavity 7 in order to make cer-
tain of pure inflammable mixture for the igniting tube. This is
the more necessary as the igniting tube operates without requiring
a timing valve.
The gas valve is shown
at 8, fig. 149, and it is
operated by the lever 9,
the governor 10 controlling
the gas supply in the usual
manner. The ignition tube
1 1 remains at all times open
to the engine cylinder, and
the time of ignition is ad-
justed by the position of
the incandescent part of
the tube. To vary this
position the Bunsen burner
is moved upwards or
downwards as required,
adjustment of ignition is obtained in this
FIG. 149.— Barker's Otto Engine
(end elevation).
A very accurate
way.
The air supply is admitted to the annulus 12, and it passes
through apertures in the sleeve carrying the admission valve.
The exhaust gases are discharged by way of the pipe 13.
The engine illustrated is of 12 HP nominal, and it gives
excellent results, as may be seen from the accompanying dia-
grams, figs. 150 and 151. Fig. 150 is a diagram taken with
the engine fully loaded, and fig. 151 with the engine running
light without load. The timing of the ignition when running
without load is as perfect as when full load is carried. These
two diagrams prove that the open tube igniter without timing
Otto Cycle Gas Engines
329
valve is quite capable of producing accurately timed explosions
under widely varying conditions of temperature and compqsition
of mixture.
Diagrams and Gas Consumption. — An engine of the kind
illustrated was tested at the Saltley Gas Works of the Birmingham
Corporation at the beginning of 1894 by Mr. J. W. Morrison.
Fig. 152 is one of the diagrams then obtained with the principal
results of the test marked under it. From this it appears that
the engine consumed as an average of four experiments 21-3
r.300 ,
MP 76 LBS
Nominal HP, 12 ; diam. of cylinder, TO" ; length of stroke, 18' ; revs, per min. 180 ;
indicated HP, 24 4 , consumpt per I HP per hour. 18 cb. ft. ; consumpt. per BHP
per hour, 21*5 cb. ft. ; mean pressure, 76 Ibs. ; max. pressure, 250 Ibs. ; pressure
before ignition, 51 Ibs. : scale of spring ^\~' per Ib
Fig. 150. — Full Load Diagram. 12 NHP Barker Otto Engine.
cb. ft. of gas per brake HP per hour, or 17*2 cb. ft. per IHP
hour This is an admirable result with Birmingham gas. As the
compression was only 50 Ibs.. it is evident that much of the
efficiency of the engine was due to the very good arrangement of
the combustion space and valves. This engine was designed
for Messrs. Barker by Mr, E W Lan Chester In the author's
opinion Mr Lanchester is to be congratulated on the excellence
of the results. At the time the test was made the author believes
the consumption to be the lowest then recorded.
Tangye? Otto Engine. — The Otto gas engine constructed by
330 The Gas Engine
Messrs. Tangye does not appear to have any features calling for
special mention. In the smaller engines Pinkney's ingenious
—300
Scale of spring, ^5" per Ib. ; rev. per min. 194 ; running light.
FIG. 151.— No Load Diagram. 12 NHP Barker Otto Engine.
momentum governor, described on page 235 of this work, is
adapted to the Otto cycle, but in the larger engines the centrifugal
IQO
120
60
MR 68 5 LBS.
Maximum brake HP, 30 ; diam. of cylinder, 12" ; length of stroke, 20" ; indicated
HP, 36-6 ; consumpt. per IHP per hour, 17-7 cb. ft. ; brake HP, 29*8 ; consumpt.
per BHP per hour, 21 '8 cb. ft. ; mean pressure, 68*5 Ibs. ; max. pressure, 180 Ibs. ;
pressure before ignition, 50 Ibs. ; rev. per min. 207^25 ; scale of spring, ^5" per Ib.
FiG. 152. — Saltley Diagram. Barker Otto Engine.
governor is used. The combustion chamber also is somewhat
conical instead of being cylindrical. Indeed, Messrs. Tangye
appear to claim special advantages in silencing the explosion by
Otto Cycle Gas Engines
332 The Gas Engine
means of this conical shape ; no doubt a conical chamber does
possess certain advantages, and these advantages were fully
appreciated by the author as early as the year 1880, as may be
seen by examining the section of his engine on page 187 of this
work.
Messrs. Tangye's engine is well made, and the design is
characteristic. Fig. 153 illustrates the general appearance of the
engine, and fig. 154 is a diagram which Messrs. Tangye were
good enough to send the author, giving the results claimed by
them for a large gas engine.
Nominal HP, 35 ; diam. of cylinder, 18" ; length of stroke, 24" ; rev. per min. 160 ;
consumpt. per IHP per hour, 14*7 cb. ft. ; 3 explosions per cb. ft. of town gas;
mean pressure, 89 Ibs. ; max. pressure, 220 Ibs. ; initial pressure before ignition,
73 Ibs. ; scale of spring, gV'.
FIG. 154. — Diagram from 35 NHP Tangyes' Otto Engine.
Burfs Compound Otto Engine. — Many attempts have been
made to utilise the compound principle in the gas engine in order
to expand the compressed charge to a greater volume than that
existing before compression. Otto, Crossley, Atkinson, Clerk
and many others have experimented in this direction, but so far
without success. The engine known as Burt's Acme Compound
Engine is in reality an expansion engine and not a compound, as
in it the full initial pressure is applied to both cylinders. That is,
both pistons get the maximum pressure of the explosion ; the
Otto Cycle Gas Engines 333
pistons between them, however, expand the compressed gases to a
greater volume than their volume before compression, and so the
engine is well worthy of study by engineers interested in some
difficulties of compound gas engines.
Professor W. T. Rowden, writing on a report on the engine
giving the results of a test made in Glasgow, says : * The chief
novelty in the engine is the method of obtaining expansion of the
fired charge beyond the volume occupied by the mixed gases at
the end of the intake portion of the cycle.
' From the Otto and Clerk engines, and from others which are
more or less copies of these two types, the products of combustion
begin to escape whilst still at a pressure of from 30 to 40 Ibs.
above atmosphere. The " Acme " engine secures the desired
expansion in a simple manner, and the exhaust is almost noiseless.
Moreover, the temperature of the exhausted gases is so reduced
by the cooling effect of the expansion as to remove all danger of
fire from a heated exhaust pipe. Referring to the engraving
of a 2 HP (nominal) engine [see fig. 155], it will be seen that
two cylinders, pistons and shafts are used, the two shafts being
connected by toothed wheels, which are geared in the ratio of
2 to i. The piston of the cylinder seen on the right, which is
connected to the slow moving shaft, sweeps a less volume than
the other does, besides making only half the number of strokes.
This smaller volume is secured either by shortening the crank or
lessening the diameter of the cylinder, or by the two combined.
The two wheels are engaged so that when the fast-moving piston
(on left) is at its outer and inner dead points, the other is distant
from its dead points by a distance corresponding to a motion of
about 45 degrees of its crank, an amount of travel corresponding
roughly to one-seventh of the whole stroke. This piston regulates
the firing and the exhaust by having the firing tube inserted
through the cylinder at about one-seventh of its stroke from the
inner dead point, and having ports opening from the cylinder at
the outer seventh. Thus only one valve is required, namely, an
automatic lift valve for admitting the charge of gas and air, and
for preventing the formation of a partial vacuum in the cylinders
when the engine misses an explosion by being governed.'
By this clever device of two pistons operated by cranks geared
334 The Gas Engine
together in the ratio of two to one, the Acme engine succeeded in
getting a considerable range of expansion beyond that given by
other engines.
Figs. 156, 157 and 158 are respectively side elevation, sec-
tional plan and end elevation of a 12 HP nominal engine.
The cylinder i is open at all times to the cylinder 2 by the
wide short port 3, and the piston A in cylinder i makes double
FIG. 155. — Burt's Compound Otto Engine.
the number of strokes of the piston B in the cylinder 2. The
crank A1 connects to the piston A, and the crank B1 to the piston
B ; these cranks, as will be seen, have separate shafts, which are
geared together by the toothed wheels c. The automatic lift valve
4 admits a mixture of gas and air to both cylinders by way of
the port 5, and and this valve 4 is supplied with gas by way of
the valve 6 (fig. 156). The gas valve is controlled by the inertia
Otto Cycle Gas Engines
335
governor 7, which causes the blade 8 to miss the gas valve stem 6
when it is necessary to cut out ignitions. The tube igniter 9 opens
into the cylinder 2, and is uncovered at the proper time for ignition
be
G
w
by the piston B ; that is about the position shown in the drawing,
the piston B one- seventh on its forward stroke, and the piston A
just on the in -centre. During the time the piston A is making its
complete out-stroke, the piston B has moved out about f of its
336
The Gas Engine
stroke, and has uncovered the ports 10, which are the exhaust
ports. These ports are cylinder ports such as were used in the
Clerk engine. The pressure in both cylinders then falls to
atmosphere, and the piston A makes its return stroke, while the
piston B is uncovering the ports 10 and covering them again. The
piston B is just closing the ports 10 when the piston A completes
its exhausting stroke, and the next out-stroke of A draws into the
cylinder a mixture of gas and air by way of the automatic lift
valve 4, and when the out charging stroke is completed the piston
B covers the igniter tube port and does not uncover it till com-
Otto Cycle Gas Engines
337
pression is completed. It is easy to see that by proportioning
the stroke and diameter of the piston B to that of A, any desired
expansion of the charge may be obtained.
Fig. 159 is a diagram from the cylinder 2, while fig. 160 is
one from the cylinder i, of a 12 HP engine similar to the
illustrations, taken by Prof. Jamieson of Glasgow. The results of
the test are marked under the diagram fig. 160. An examination
of the two diagrams shows clearly the action of the engine. Com-
pression begins when the piston B has nearly reached the end of
FIG. 158. — Burt's Compound Otto Engine (end elevation).
its stroke and continues while the piston moves out from a to b, fig.
159, that is the piston A is compressing its charge partly into the
clearance space at the end of its cylinder and partly into the
cylinder 2 by way of the port 3, so that the piston B is running
away from the piston A, and is being followed up by the compres-
sion. At b the charge ignites and the pressure rises to the same
point in both cylinders, the piston B continues to move out and
is followed by the piston A, which piston, however, speedily over-
takes it, so that it finishes its stroke before the piston B moves out
enough to uncover the exhaust ports 10 on the side of the cylinder ;
z
338
The Gas Engine
the pressure then falls to atmosphere very gently, as shown by
the drop on the diagram fig. 159 at the points The diagram
fig. 1 60 looks like an ordinary Otto diagram, but in interpreting
its indications the diagram fig. 159 must be duly considered.
ISO
120
Nominal HP, 12 ; short stroke cylinder, 10" diam. x n" stroke ; spring TJS" per Ib. ;
max. pressure, 158 Ibs. ; pressure before ignition at &, 48 Ibs.
FIG. 159. — Diagram from Cylinder 2 Burt's Compound Otto.
According to Prof. Jamieson's test of April 8, 1892, the 12 HP
engine gave 13 brake HP on a consumption of 19-3 cb. ft. per
brake HP per hour of Glasgow gas.
Prof. Rowden made a test of a smaller engine of 6 HP
nominal at the establishment of Messrs. Herbert Bros., corn
150
120
90
60
30
Nominal HP, 12 ; long stroke cylinder, n|"diam. X2o" stroke ; rev. per min. 160 ;
brake HP, 13 ; consumpt. per BHP hour, 19-3 cb. ft. ; max. pressure, 158 Ibs. ;
pressure before ignition, 48 Ibs. ; scale of spring, T£o" per Ib.
FIG. 1 60. —Diagram from Cylinder I Burt's Compound Otto.
merchants, Kennedy Street, Glasgow, and obtained 8*28 brake
HP on a consumption of 17-3 cb. ft. of gas per brake HP
hour, the faster crank running at 170 revolutions per minute.
The * Acme Compound ' engine may therefore be taken to have
consumed about 19 cb. ft. of Glasgow gas per brake HP hour ;
Otto Cycle Gas Engines 339
this corresponds to about 21 cb. ft. of Birmingham gas, so that
the results are very creditable.
General Remarks. — This engine has been replaced by the
Messrs. Burt's Otto engine of more usual type. The engine,
although called compound, was not really a compound because
both cylinders served as high and low pressure cylinders
simultaneously. It seems to the author that an engine cannot
be truly termed ' compound ' unless it includes separate high-
pressure and low-pressure cylinders. The advantages to be ob-
tained by the compound engine in saving weight and strength .of
engine cannot be gained without the use of a small cylinder to
operate at high pressure and a large cylinder to operate at low
pressure. This engine was necessarily heavy for its power, and it
p'80
Nominal HP, 6 ; diam. of cylinder, g\" ; length of stroke, 16" ; rev. per min. 180 ;
consumpt. per IHP hour, IS'DS cb. l"t. ; consumpt. per BHP hour, 2o'8o8 cb. ft. ;
scale of spring, T|5" per Ib. ; max. pressure, 171 Ibs. ; prtssure before ignition,
69 Ibs.
FIG. 161. — Diagram from 6 NHP Burt's Otto Engine.
had the great disadvantage of requiring gear wheels, which wheels
had to take the whole strain of the explosion.
The engine is, however, very clever and interesting, and the
author has described it at some length because of some lessons it
teaches, which will be referred to in a later chapter, when com-
pounding is discussed.
Burfs Otto Engine. — Messrs. Burt & Co. now manufacture
Otto gas engines of more usual construction, but instead of the
ordinary lift valves they adopt a piston valve driven from the
valve shaft by a small crank. They obtain fair results with those
engines, as will be seen from diagram fig. 161, in which a 6 HP
engine shows a consumption of 15*03 cb. ft. of Glasgow gas per
IHP hour, and 20-8 cb. ft. per brake HP hour. It is to be kept
in mind that Glasgow gas is of higher heat value than most
z 2
340
The Gas Engine
samples of English gas, but it is not so high now (1895) as it was
in 1885, as the standard has been reduced.
FIG. 162. — Burt's High Speed Otto Engine (vertical section).
Messrs. Burt & Co. have recently built a high-speed gas
engine, of which a vertical section is given at fig. 162, which is
especially interesting, as it approaches so closely to steam engine
Otto Cycle Gas Engines 341
lines. Two pistons i and 2 are arranged tandem fashion on the
same piston rod 3 ; a common connecting rod 4 serves for both
and actuates a crank 5. The upper sides of the pistons are used
for the power impulses, and the lower sides operate idly moving
air to and fro ; both pistons operate on the Otto cycle, but the
impulses are arranged to alternate. The crank thus gets an
impulse at every revolution when the engine is under full load.
The crank shaft carries a wheel 6 gearing into a wheel 7, from
which the piston valve is driven at half the number of strokes
of the main crank. The action and function of these piston
valves are very peculiar. The pistons i and 2, it will be seen,
approach their cylinder covers as nearly as steam engine pistons,
and the main combustion space is formed by the ports and pas-
sages leading to the valves, and also by the annular space formed
between the piston valve stems 9 and the cylinder. When the
upper piston i is in the position shown in the figure, it will be seen
that the cylinder is open to the annular space formed round the
piston valve stem 9, and between the piston ports of the valve.
These spaces form the combustion chamber, and the explosive
mixture is compressed into them and ignited by the tube igniter
10. When the piston i has made its power stroke down, the
piston valve moves to bring into connection the ports n and 12,
and the piston i then moves up and discharges the exhaust pro-
ducts ; on the next down stroke the piston valve again takes the
position shown by the upper valve, and the lower valve 13 is
opened to admit a charge of gas and air on the next down stroke.
The piston 2, as shown on the drawing, is just finishing its ex-
hausting stroke, and the piston valve is about to close the exhaust
port. The valve arrangements of piston 2 are similar to those of
piston i.
This engine is most interesting for many reasons ; its designers
are very daring, and appear to the author to disregard some of
the understood conditions of gas engine economy. It appears to
him impossible to obtain any high economy in gas consumption
from an engine with its combustion spaces made up of tortuous
ports and passages. The engine gives the designer an extreme
example in the direction of subdividing the combustion space,
and it will certainly be interesting to know its power and gas
342
The Gas Engine
consumption. Fig. 163 gives diagrams taken from the top and
bottom cylinders at 400 and 480 revolutions respectively.
Robefs Otto Engine. — Messrs. Robey & Co. now build Otto
engines up to a brake power of 120 horse.
Figure 164 shows their engine as made from 36 brake horse
-200
100
zo
216
Top cylinder, 400 revs, per min.
18
Bottom cylinder, 480 revs, per min.
FIG. 163. — Diagrams from Top and Bottom Cylinders,
Burt's High Speed Engine.
to 120 ; the bed of the engine is of the Corliss type, and like all
this maker's engines the design is pleasing and workmanlike.
The exhaust valve opens directly into the combustion chamber,
and so avoids port clearance spaces. This valve is removed by
lifting a cap placed on the upper side of the cylinder and pulling
the exhaust valve through, after removing the lever connections.
Otto Cycle Gas Engines
343
344 The Gas Engine
The charge inlet valve opens into a port at the end of the combus-
tion chamber, and it also is removed by way of a cover placed
above it. This system avoids the use of heavy sleeves which
require to be taken out from below : such sleeves being very
inconvenient in large engines.
Ignition is effected by an incandescent tube, controlled by
the usual timing valve. Messrs. Robey use a compression pres-
sure of 60 Ibs. per square inch.
Wells Brothers' Otto Engine. — Messrs. Wells Brothers build
Otto cycle engines up to 1 20 HP. They make their engines of three
main types ; the smaller engines up to and including 16 nominal
HP are made on the usual Otto cycle without scavenging ;
engines of 20 nominal HP and above are made with a scavenging
arrangement to displace the exhaust products. The front end of
the piston is enlarged and forms an annular cylinder which serves
as an air pump. On the return stroke the air is discharged from
the annulus, and passed through the combustion space of the
cylinder so as to displace the burnt gases by pure air. For
ordinary work the engine is made with a single cylinder, but for
electric lighting two cylinders are used arranged in tandem.
Fig. 165 shows in elevation an engine of the tandem type capable
of indicating 120 HP with Dowson gas. The engine is con-
structed and operates as follows. The front motor piston has a
large end which works in the bored bedplate ; to this end the
connecting rod is attached, so that it acts as a guide block. Two
side rods are secured to the end and passed backwards alongside
the cylinder liner through a passage way cast in the water jacket :
thence they pass through bushes having light spring rings and
secured at their rear ends to the crosshead of the back piston. The
large piston acts as an air pump, but a free passage to the atmo-
sphere is provided during the first part of the back stroke, so that
the air intended for scavenging is only compressed and passed
through the combustion chamber towards the end of the exhaust
stroke. As the cylinders make exhaust strokes alternately, and
the large piston forces air through the air passage leading to both
cylinders at every back stroke, the air is discharged through
whichever of the motor cylinders is in its exhaust stroke.
The governor is of the high speed spring loaded centrifugal
Otto Cycle Gas Engines
345
346 The Gas Engine
type, and is driven by a bevil wheel on the crank shaft ; it controls-
upright hit and miss rods in such a manner that the gas is cut out
from one cylinder before the other. The proportion of gas ad-
mitted is also varied between narrow limits by graduated notches,,
which determine the lift of the gas valves. The engine has twa
flywheels and outside adjustable bearings, positive ratchet feed
lubricators for the cylinders, and an oil box on the splash guard,
and sight drop feed supply to the main bearings and to the crank
pin by a centrifugal oiler. This engine is interesting, and it gives
economical results. Messrs. Wells have supplied the author with
the following particulars of a test made in their workshops with
Nottingham coal gas :
TEST OF A 60 BHP WELLS TANDEM ENGINE.
Diameter of cylinders 12 inches
Stroke . . 18
Speed 164 revs, per min.
( front 82 per min.
Explosions -(back ( ;g M
Mean effective pressure 90 Ibs^ per sq. inch
Load on brake wheels ..... 578 Ibs. nett
Circumference brake circle . . . 22 '3 feet
Gas consumption per hour . . . 1,190 cubic feet
Indicated horse power . . . . 73 '9
Brake horse power . . . . "y 64/0
Gas per IHP per hour . . . . . i6'i cubic feet
Gas per BHP per hour 18*6
These results are very satisfactory, and prove Messrs. Wells'
engine to be an economical one.
Fielding 6° Platfs Otto Engine. — Messrs. Fielding and
Platt build Otto cycle engines up to 200 indicated HP, the larger
engines being of the tandem type. From the largest engine they
obtain 170 brake horse power at full load, and by their system of
governing for electric light purposes they claim that the maximum
speed variation between running light and full load does not
exceed three per cent. To accomplish this the engine is governed
without cutting off the gas ; power impulses are given continuously,
but reduced in strength to meet the variation in load. The gas
and air supply valves are regulated separately, the governor
reducing the gas and air simultaneously. The combustible mixture-
Otto Cycle Gas Engines 347
supplied to the engine is thus kept practically constant as to the
relative amounts of gas and air, but the volume supplied is
diminished and so reduces the compression. The compression
varies from about 5 Ibs. above atmosphere to 60 Ibs. and ac-
cordingly the explosion diagram varies within wide limits, so
wide indeed that it is never necessary to miss impulses. The
consumption is of course increased per indicated HP for light
loads, but there are many cases where such increase is quite per-
missible. The idea is one worthy of consideration where great
regularity is required.
Self-starting Gear.— Before leaving the mechanism of the Otto
cycle engines, it is desirable to describe shortly the starting gears
which are now used for such engines. The great increase in the
power of the engines manufactured has made it imperatively
necessary to provide starting devices which dispense with the old
method of starting by hand.
The first gas engine starting gear introduced in this country
was the invention of the author, and was applied to the Clerk
impulse-every-revolution engine, as described at p. 239 of the
earlier part of this work. That starter required to store up air or
gas and air mixture under compression, and this was found to
involve expensive arrangements, so that although the gear was
quite satisfactory in action its first cost was too high.
The starting gear now the most extensively used is also the
invention of the author ; the patent has been acquired by the
Messrs. Crossley, and the Clerk starter is now used by them in
all engines of sufficient dimensions to require a starter.
Fig. 166 is a diagrammatic section illustrating its action. A is
the gas engine cylinder ; B a check valve opening into the exhaust
port ; D a chamber connected by the pipe D1 to the valve B ; and i
is an igniting valve. K is a port leading to a charging pump.
The object of the device is to fill the combustion space of the
engine with a compressed mixture of gas and air, and then to
explode that compressed mixture and so provide a high-pressure
explosion to give the starting impulse.
To start : the engine crank is placed well off the centre ; the
pump is operated by hand to fill the chamber D, pipe D1 and
cylinder A with gas and air mixture at atmospheric pressure ', so that
348
The Gas Engine
no resistance is experienced during the operation of the pump.
After charging, the igniter is operated, and the mixture in the
chamber D ignites at the end near i ; the flame as it spreads
through the chamber forces the unburned mixture before it into
the pipe D1 through the valve B into the cylinder A, so that when
the flame arrives at the valve B it has swept before it into the
cylinder all the unburned mixture, and when the flame passes the
valve B it ignites the compressed mixture in the cylinder and
produces a high-pressure explosion which starts off the engine
with an ample margin of power to overcome the friction of
belting and shafting.
In conjunction with Mr. F. W. Lanchester the author has
FIG. 1 66. —Clerk Flame Starter.
produced a modification of this starting gear which is known as
Clerk-Lanchester starting gear, and it is illustrated in diagrammatic
section at fig. 167. In this arrangement the igniting valve Y is
adopted, which is the invention of Mr. Lanchester. The pump
for charging th^ starting chamber is also dispensed with.
The action is as follows : When the engine is stopping, while it
is making the last few revolutions with the gas turned off, the valve
w is opened and air is drawn through the chamber D by way of
the valve Y at every suction stroke. The chamber D, pipe D' and
cylinder A thus become filled with pure air at atmospheric
pressure. When the engine is to be started the gas cock F is
opened and gas flows from the gas main pipe at G into the cham-
Otto Cycle Gas Engines
349
ber D and at H into the pipe D', a cock on the cylinder being
opened to allow flow into the cylinder, or the exhaust valve is held
slightly open. The flame x burns across the valve Y, and after a
few seconds mixture of gas and air escapes through Y and burns
in the air. The cock F is then closed, and the flame shoots back
past the valve Y, and so ignites the mixture within D, closing the
valve Y against an upper face by the force of the explosion. The
flame then proceeds along D, D' into the cylinder A, firing the mix-
ture it has compressed before it, and so the engine is started by a
compression explosion.
Fig. 1 68 is a starting diagram obtained from this arrangement.
FIG. 167 — Clerk-Lanchester Starter (diagrammatic section).
From the diagram it will be observed that a maximum pressure of
200 Ibs. per square inch is attained, giving an available starting pres-
sure of 80 Ibs. per square inch, a pressure amply sufficient to start a
gas engine, even allowing for the friction of a line of shafting.
The great advantage of the Clerk or Clerk-Lanchester starter
is due to the ease with which a compression explosion is obtained
without the necessity of storing up compressed gases or compress-
ing gases by manual labour.
The Lanchester low-pressure starter is also extensively used
when it is not considered necessary to obtain a high-pressure ex-
plosion. Fig. 169 is a diagrammatic section of this starter, and
fig. 170 is an indicator diagram showing the first and succeeding
350
The Gas Engine
starting explosions. The Lanchester low-pressure starter is un-
doubtedly the simplest gas engine starting device which has ever
been produced. It requires no addition to the engine save a gas
admission cock and jet, and a mixture sampling and igniting cock.
.200
150
100
50
FIG. 168. — Clerk Starter Diagram. Initial pressure, 200 Ibs. per sq. in.
Average available pressure, 80 Ibs.
The engine cylinder A has mounted upon it the sampling and
igniting cock i shown on a larger scale in section at 2 ; the cylinder
is also supplied with a gas admission jet 3, fitted with a cock.
FIG. 169. — Lanchester Starter (diagrammatic sections).
When the gas is shut off to stop the engine the cylinder is filled with
pure air, and so it remains filled with air at atmospheric pressure.
When the engine is to be started, the crank is set well above the
centre, the cock 3 is opened to the gas supply, the cock i is also
Otto Cycle Gas Engines
351
opened and the jet 4 is lit ; the gas then flows into the cylinder A,
mixing with the air in the cylinder and displacing some air through
the valve chamber B (section) ; in this chamber B is fitted a double-
seated valve, which usually by its weight rests upon the lower seat ;
grooves are cut round it and along its lower face to allow gases to
flow past it while it rests on its lower seat. When the gas jet is
first turned on air only flows through, but after a few seconds gas
mixture follows and is ignited by the jet 4. The mixture burns as
shown, and as it becomes richer in gas the flame changes its
colour and burns with a sharp roar ; the cock 3 is then turned off,
and the flame shoots back into the cylinder and ignites the mix-
ture existing at atmospheric pressure within it. The explosion at
once slams the valve B against its upper seat and so closes it. The
engine then starts under the pressure of the low-pressure explosion.
FIG. 170. — Lanchester Starter Diagrams.
At fig. 170 the diagram a shows the first explosion, and it will be
observed that other diagrams b follow the first explosion. These
explosions are produced by the action of the igniter. When
the engine moves by the first explosion, the piston on its return
discharges the exhaust in the usual manner ; on the next out-stroke
it takes in the usual charge of gas and air. On the next return
stroke, however, which would be the ordinary compressing stroke,
the exhaust valve is held open during the whole stroke, and so the
combustion space is left at the end of the stroke filled with a
mixture of gas and air under no compression. During this back
stroke some of the mixture flows through the jet i, and is ignited at
the flame, and so soon as the piston begins to move out again the
flame shoots back, and another low-pressure explosion occurs,
as shown at £, fig. 170. In this manner a series of low-pressure
352 The Gas Engine
explosions are obtained sufficient to get up the speed of the engine
to a point at which the compression may be safely applied and the
engine caused to perform its ordinary cycle. The Lanchester
starter is much used, and is very successful when the friction of
the engine and its connections is not too great.
Other Self-starting Devices. — The Lanchester and Clerk starters
may be taken as the typical starters of to-day, and they are applied
much more extensively than any other types. Most makers,
however, now supply with their engines self-starters of some kind.
Messrs. T. B. Barker & Co. and Messrs. Robey & Co. use the
Lanchester starter. Messrs. J. E. H. Andrew & Co. also employ
a low-pressure starter which resembles Lanchester's in its leading
features. The igniting device is connected with the ordinary
igniter tube. Fig. 138, page 320, shows this arrangement in section.
The igniter tube G is fitted with an internal directing tube
communicating behind the timing valve F. A gas supply cock
with its jet somewhat similar to 3, fig. 169, is applied to the engine
cylinder. When it is desired to start, the engine crank is set well
off the centre as usual, the tube G is heated to incandescence and
the valve A fig. 138 is opened to the, atmosphere. The valve F
is also opened in towards the cylinder. Gas then flows into the
cylinder, mixes with the air within it as with the Lanchester
device, and in entering it displaces air first and inflammable mixture
afterwards past the valve F up the internal directing tube into the
igniter tube G, then away in the direction shown by the arrows to
the valve A and past that valve to the atmosphere. When the
mixture becomes inflammable enough, the gas supply is cut off
and the igniter tube ignites the mixture, then the valve A closes
upon explosion. By this neat device Messrs. Andrew obtain their
low-pressure starting explosion. The whole arrangement resembles
Lanchester's except in the rather neat device for utilising the ordinary
igniter tube c to obtain the starting explosion as well as the
ordinary explosions.
Messrs. Tangye adopt a somewhat more complex method of
starting ; they set the engine crank on the in-centre, then pump a
mixture of gas and air into the cylinder till the pressure approaches
the usual pressure of compression ; they then simultaneously move
the crank off the centre and admit the compressed charge to the
Otto Cycle Gas Engines 353
igniter. They thus start with a compression explosion. This
starter, it appears to the author, is open to the objection that in
the event of a slight leak in the piston the man operating the hand
pump may be unable to pump fast enough to obtain the necessary
compression.
Messrs. Fielding & Platt utilise a starter which in one feature
resembles the old Clerk starter described on p. 239, They cause
the engine to compress air into a reservoir to a pressure of about
60 Ibs. per sq. inch and store this pressure up till wanted. To start,
the engine is put orTthe centre and the cylinder is filled with pure gas
or a mixture at atmospheric pressure so rich in gas that it is non-
explosive. The air under pressure is then admitted to the cylinder
and forms an explosive mixture under pressure, which mixture is
ignited in the usual way by an igniter tube to give the starting
explosion.
A A
354 The Gas Engine
CHAPTER III.
THE PRODUCTION OF GAS FOR MOTIVE POWER.
IT has been already pointed out by the author in the earlier part
of this work, that the unit of heat supplied in the form of ordinary
coal gas is more costly than the unit of heat supplied in the form
of coal, and that accordingly the gas engine remains at a disadvan-
tage as compared with the steam engine till the time comes when
the gas unit of heat costs no more than the coal unit. This fact
has been recognised by many inventors, and numerous attempts
have been made to produce cheaper gas. Mr. J. E. Dowson,
however, is the only inventor who has made much headway in this
subject, and his producers are now largely employed for generating
gas for gas engines of large powers. Mr. Dowson has, however, only
effected a partial solution of the problem, as his producers can only
use two kinds of fuel, anthracite and coke. Of the two his pro-
ducer acts better with anthracite ; with coke its performance cannot
be said to be entirely satisfactory. The disadvantage of more
expensive heat unit is not felt in small gas engines, because the
governing of the engine and the heat efficiency is so much superior
to any small steam engine that even in actual expense of fuel the
gas engine is superior. The attendance required is also trifling
compared with the steam engine. Accordingly it is quite un-
necessary to trouble about gas other than towns gas for engines
under twenty horse power. Engines giving out that power or any
power above that and working steadily at full load require cheaper
gas to compete with the steam engine. It would not be difficult,
for example, to work a steam engine giving 100 horse power at
3 Ibs. of coal per IHP hour, the coal costing not more than los.
per ton ; this gives an expenditure for coal of 0*16 penny per HP
The Production of Gas for Motive Power 355
hour. A gas engine of 100 horse power would use about i^ Ib.1
of anthracite costing 2os. per ton, and here the fuel would cost
0-15 penny per HP hour. That is, assuming that the gas engine
and producer cost as much for attendance, repairs and oil as the
steam engine and boiler of corresponding power, it would just
compete favourably with a steam engine using 3 Ibs. of coal
per indicated horse power. The gas engine, however, has a con-
siderable advantage even when supplied by gas producers in
working at light loads, and its consumption at such loads is
proportionately less than the steam engine. If, however, gas
producers could be made which would effectively produce gas
from cheaper fuel, or fuel such as the slack generally used for
steam boilers, then the gas engine would have an overwhelming
superiority over the steam engine from a pecuniary point of view
in large engines as well as small.
The gas producer problem is, therefore, one which will doubt-
less very considerably exercise the attention of inventors. Accord-
ingly the author will now shortly discuss the principles of the
subject, and then describe the Dowson and another producer and
some of their difficulties.
Ordinary town illuminating gas is produced by the destructive
distillation of suitable coal. The object of the manufacturer is to
produce a gas capable of burning with a bright illuminating flame.
It is a purely accidental circumstance that such illuminating gas
has also been found very suitable for generating motive power.
Accordingly, it is not to be expected that coal gas should be gene-
rated under the best economic conditions for cheap motive power.
Gas-making coal is necessarily more expensive than the fuel
ordinarily used in steam boilers, and further the process of destruc-
tive distillation can only liberate from the coal such volatile
matters as enter into its composition. The amount of gas so
obtained per ton of coal depends on the temperature of distillation,
or the temperature of carbonisation as the gas engineers call it
At a comparatively high temperature a larger volume of gas is given
off per ton, but the percentage of illuminating gases present are
reduced, and so the illuminating power is low. A good gas coal
on destructive distillation will yield at a fair carbonising temperature
1 Under I Ib. per I HP hour has been claimed by Mr. Dowson.
A A 2
356 The Gas Engine
from 10,000 to 11,000 cb. ft. of gas per ton of coal of from 15
to 17 candle power, and it will leave in the retort about 62 to 73
per cent, of coke ; that is, of 100 tons of the original gas coal 38
to 27 tons are driven off as illuminating gas, vapour, tar, ammonia,
water, &c., while 62 to 73 tons remain in the retort as coke. So
long, then, as the ordinary process of destructive distillation is
adopted, the heat unit of coal gas supplied to a gas engine must
necessarily be more expensive than the heat unit evolved in the
furnace of a steam boiler, because more fuel and that more expen-
sive fuel is required apart altogether from the cost of the distribu-
tion of the gas from the gas works. To compete with the steam
boiler and furnace in producing a gas heat unit as cheaply as a
coal heat unit placed on the fire grate, it is necessary to convert
the whole of trie coal into gas suitable for use in a gas engine.
At first glance it appears a difficult problem to produce inflam-
mable gas from solid carbon either in the form of anthracite or of
coke, but the principle is simple enough. When unit weight of
carbon is entirely burned in air or oxygen, carbonic acid, or more
properly carbonic anhydride, is formed, that is the gas CO2. This
gas CO2 if passed through a sufficient depth of incandescent carbon
is converted into the gas carbonic oxide, which is inflammable. The
chemical reaction is generally given :
C02 + C=2CO.
That is, two volumes of CO2 combined with a sufficient weight
of carbon to form carbonic oxide produce four volumes of carbonic
oxide gas. For the purpose of the gas engine using a properly
proportioned gas generator it may be considered that the carbon
used is burned to carbonic oxide only and not to carbonic acid.
The heat evolved in the process of producing carbonic oxide
from carbon is
Unit weight of carbon forming CO evolves 2400 heat units,
but
Unit weight of carbon forming CO.> evolves 8000 heat units,
so that the process of the formation of carbonic oxide loses a part
of the heat of the carbon, and the same weight of carbon in
carbonic oxide will only produce when the carbonic oxide is
burned 5,600 heat units instead of 8,000. Thus by passing air
The Production of Gas for Motive Power 357
through incandescent carbon or coke of a sufficient depth, carbonic
oxide gas can be formed and the whole of the carbon transformed
into an inflammable gas. The air on first coming into contact
with the incandescent carbon burns a portion of it to CO2, carbonic
acid gas, and this carbonic acid on passing through a further body
of incandescent carbon is reduced to the inflammable gas carbonic
oxide, CO. The first stage of the process evolves all the heat of
combustion, and the second stage absorbs a portion of the heat
so evolved. The net result is that if the inflammable gas produced
be cooled down and then burned in a gas engine cylinder, the heat
evolved by the combustion will only be 70 per cent, of the heat
which the solid carbon would have evolved if burned directly with-
out preliminary conversion into gas. The 30 per cent, of heat is
carried away by the carbonic oxide from the gas producer, and is
lost on cooling down the gas to suit it for use in the gas engine.
When air is blown through the producer the nitrogen of the air of
course remains, and is mixed with the inflammable CO. This is
the fundamental idea of the gas producer, and accordingly it will
be found that the earlier and abortive proposals for the conversion
of the entire solid fuel into gas contemplated only blowing air
through a sufficient depth *of carbon. Taking the composition of
atmospheric air as 4 vols. nitrogen and i vol. oxygen (the new
element argon may be neglected, as it is included in the nitrogen
and is very similar to it), then the best gas which could be produced
in this simple manner would be that in which the whole of the
oxygen was used up in forming carbonic oxide. Remembering
that i vol. of oxygen gas after combining with enough carbon to
make CO forms 2 vols. of that gas, the composition of the gas
proceeding from the producer would be 4 vols. nitrogen and
2 vols. carbonic oxide, that is :
4 vols. nitrogen = 66 '6 per cen
2 vols. carbonic oxide = 33 -3 , ,
lOO'O
The gas obtained would consist entirely of 66'6 per cent, of
nitrogen and 33-3 per cent, of carbonic oxide ; this gas on com-
bustion in the engine would evolve 70 per cent, of the heat of the
original carbon. That is, if the efficiency of the producer be
compared with a steam boiler, it would be equal to that of a boiler
358 The Gas Engine
giving 70 per cent, of the heat of combustion in its furnace in the
form of steam delivered at the stop valve.
Such a producer, however, would waste an entirely unneces-
sary amount of heat, and would give considerable practical difficulty
in getting rid of the 30 per cent, of the heat of all the carbon
gasefied in it, the lining would be overheated, and generally the
temperature of the carbon contained in the producer would be-
come undesirably intense. A certain high temperature is required,
it is true, to convert the CO2 into CO, but if that temperature be
maintained it is undesirable to go above it. Gas engineers have
accordingly taken advantage of another chemical reaction to use
some of this heat and produce better gas. If steam be passed over
highly incandescent carbon, which carbon must, however, be kept
incandescent, the oxygen of the steam unites with the carbon, and
the hydrogen of the steam is liberated. The ultimate effect of the
reaction is to decompose steam and produce hydrogen and carbonic
oxide ; the reaction is as follows :
That is, 2 volumes of water vapour in contact with incandescent
carbon produce 2 volumes of hydrogen gas and two volumes of
carbonic oxide gas. This reaction, however, absorbs heat to pro-
duce the decomposition of the steam ; more heat requires to
be absorbed than is given out by the burning of the carbon
to CO.
To decompose steam containing 2 units weight of hydrogen
gas requires the absorption of 68340 heat units, and in producing
28 units weight of CO from 12 units weight of carbon there
are evolved 28800 heat units : that is, the heat evolved by the
carbonic oxide produced in the reaction is about one-half of the
total heat required. This reaction cannot therefore proceed
without a sufficient supply of heat from some source ; the best
source is the formation of CO by means of air also acting on the
carbon. To supply heat just sufficient to perform the reaction
would require the heat evolved in producing i vol. CO by air and
carbon to every 073 vol. of CO produced by the reaction of
steam on carbon. The composition of the gas so produced
would be :
The Production of Gas for Motive Power 359
-4 vo s. | prociuceci by tke reaction of the oxygen of the air on carbon.
CO = 2 vols. )
°1S' I produced by the reaction of steam upon carbon.
H = i -46 vols. »
8 -92 vols. total.
The percentage composition would be about :
N= 45-0
= 39-0
= 16-0
The production of a gas of this composition assumes that all the
heat is utilised for the purpose of the reaction and that none is
lost from the apparatus. It assumes also that all the heat carried
away by the gas after formation is returned to the air and steam
which are about to perform the reaction. This is of course im-
possible, but the calculation has been made in order to supply a
standard of comparison. Such a gas would contain the whole of
the heat of the original carbon before gasefying. In an actual
apparatus the carbon is placed in a brick-lined producer ignited and
blown up to a good heat by a forced draught ; the producer is
then closed, and steam and air blown in in definite proportions to
pass through the incandescent carbon mass. The resulting gas
passes away from the producer in a heated state and is cooled
before being sent into the gas holder. The reaction requires a
certain temperature for its continuance, so that the interior of the
producer must not fall below it ; the gas is discharged at this
temperature, and so a greater supply of air is necessary than that
calculated to make up for the heat losses.
Dow son Gas Producer. — The Dowson gas producer at present
embodies in the best way the fundamental principles and the con-
structive details necessary for the production of gas from solid fuel ;
that is, gas suitable for a gas engine.
Fig. 171 is a diagrammatic section of a Dowson gas producer
with its accompanying gas holder. Fig. 172 is an elevation part
section, and fig. 173 a plan of a gas producer in its building with
all the necessary parts to form a complete plant.
Referring to fig. 171, the producer consists of a cylindrical
casing A lined with fire brick or fire clay, and having at the
360
The Gas Engine
bottom fire bars a above a closed ash pit B ; the upper part of the
generator is closed by a metal plate on which there is mounted a
fuel hopper A1 having an internal bell valve a1 operated from the
exterior. To begin operations, the upper cover is removed from
I J
FIG. 171.— Dowson Gas Producer and Gas Holder
(diagrammatic section).
the hopper A1 and the bell valve is opened ; a fire is built upon
the bars a and air forced through it by the steam jet n and the
pipe N1 ; fuel (anthracite or coke) is slowly added from above till
the whole mass is incandescent and fills the producer to a depth
The Production of Gas for Motive Power 361
of about 1 8 inches at least. During this heating up process, gases
are given off by way of the open hopper, and they are ignited
there by means of a flame. Great care must be taken not to
inhale the issuing gas, as it contains large quantities of carbonic
oxide and is very poisonous ; it should always be ignited when it
SECTIONAL ELEVATION
FIG. 172. — Dowson Gas Producer (part in section).
flows into the producer room, as when burned it becomes harm-
less. When the fuel is quite incandescent, the inner and outer
valves of the hopper are closed and the gas flows by a pipe
through cooling and scrubbing devices, finally finding its way into
the gas holder K through the coke scrubber formed within it.
From the gas holder the gas flows through another scrubber, as
362
The Gas Engine
shown by the arrow, fig. 171, and thence passes to the engine.
The gas holder K is of usual construction with annular water seal
.and balance weights, chains and pulleys.
The complete plant for 80 HP effective is shown at figs.
172 and 173, where A is the small steam boiler fitted with
superheating tubes, which boiler supplies superheated steam to
operate the air injector B and so forces a mixture of steam and air
GENERAL PLAI4.
FIG. 173.— Dowson Gas Producer (plan).
through the incandescent fuel contained in the gas generator c.
Fuel is fed to the generator by the feeding hopper D, and the gas
formed flows from the upper part of the producer in the direction
shown by the arrow to the gas cooler F, whence it passes to the
hydraulic box H, which box is provided with an overflow i, and
thence the gas proceeds to the sawdust scrubber j, and then to
the coke scrubber K contained within the base of the gas holder.
In these figures, E is the generator fire grate, L the gas holder, M
TJie Production of Gas for Motive Power 363
the outlet from the gas holder, NN the ash pit for the generator,
and o the automatic regulator to govern the production of gas by
stopping or reducing the supply of steam with the upward move-
ment of the gas holder.
From this description it will be seen that the whole plant is
very simple, and the author can say from his own experience that
It is easily operated and requires little repair. One man can easily
attend to an 80 HP plant.
The gas produced from the Dowson producer is thus a
mixture of carbonic oxide, hydrogen, and nitrogen ; if all the
actions were carried out perfectly there would be no carbonic acid
gas present, but as all the actions are not quite up to theory some
carbonic acid is formed. A little sulphuretted hydrogen is also
formed, more with coke than with anthracite, and this has to be
removed, as sulphur in quantity would in time act on the engine
parts.
The following analysis of Dowson gas was made by Prof.
Wm. Foster ; the anthracite used in the producer was of the
cheapest kinds in small pieces :
Standard
Analysis of Dowson gas, by volume gas
(ideal)
Nitrogen, N 48*98 . . . .45-0
Carbonic oxide, CO . . . . 25-07. . . . .39-0
Hydrogen, H . . . . . 1873)
Marsh gas, CH4 . . . . '3*1
Olefiant gas, C2H4 .... -31
Carbonic acid, CO2 . . . . 6-57
Oxygen, O '03
Comparing this with a perfect producer gas, it is seen that
instead of getting 39 per cent, of carbonic oxide by volume only
25*07 is obtained ; on the other hand, when the ideal gas would only
give 16 per 'cent of hydrogen 1873 per cent, has been obtained,
and a further 0-62 per cent, of marsh gas and defiant gas. The
marsh gas and defiant gas are produced doubtless from the small
quantity of hydrogen which forms part of the original anthracite ;
anthracite contains about 3 per cent, of hydrogen. The excess of
hydrogen, however, in the gas can only arise from the fact that the
whole of the carbonic acid originally formed is not reduced to
364 The Gas Engine
carbonic oxide. This is evident from the fact that 6-57 per cent, of
carbonic acid is present. As the burning of carbon to carbonic
acid instead of to carbonic oxide involves the evolution of the
whole 100 per cent, of the heat of combustion of the carbon instead
of only 30 per cent, of it, it follows that more heat is left available
for the decomposition of water by the coke, less carbonic oxide
is formed by the action of the oxygen of the air on the carbon,
and so the proportion of carbonic oxide in the gas diminishes,
while that of hydrogen increases. A French analysis of Dowson
gas is as follows :
ANALYSIS OF DOWSON GAS PRODUCED IN FRANCE.
Nitrogen, N . . . .42-28
Carbonic oxide, CO . . - 18*20 x
Hydrogen, H .... 26*55 (.45-86 combustible.
Hydrocarbons, j ^4 I . . I'liJ
( L/2.H.4 )
Carbonic acid, CO2 . . .11-30
Oxygen 0*47
Here it will be observed that the nitrogen is still lower, and
that notwithstanding the great increase of carbonic acid gas, 1 1 -3
per cent, instead of 6-57 per cent., the hydrogen gas has increased
from 1873 per cent, to 26-55 per cent., while the carbonic oxide
has gone down from 25^07 per cent, to i8'2o. This disproportion
between the hydrogen and carbonic oxide can only arise from the
fact that carbonic oxide itself at a high temperature decomposes
steam, so that part of the carbonic oxide which would otherwise
have appeared in the mixture has disappeared, forming carbonic
acid and hydrogen ; the reaction is :
CO + H2O=CO.2 + H2.
That this is true is evident from both analyses, where there is
present a considerable proportion of carbonic acid, in one case
6-57 per cent, and in the other 1 1 -30 per cent. ; it is to be observed
that the increase of hydrogen is accompanied by an increase of
carbonic acid.
It is often stated that hydrogen is a gas of greater heating
power than carbonic oxide, but as a matter of fact for gas engine
purposes this is not so ; hydrogen, it is true, weight for weight
evolves far more heat by its combustion than any other substance,
The Production of Gas for Motive Poiver 365
but volume for volume carbonic oxide evolves rather more heat
than hydrogen. Hydrogen evolves by the combustion of i Ib.
weight 34170 heat units, or enough heat to raise 34170 Ibs. of
water through i° C., but this figure includes the heat evolved on
liquefying the steam, formed by the combustion, in the calorimeter,
which at 637 heat units per Ib. of water gives 9x637 = 5733
heat units absorbed in forming steam produced by burning i Ib.
of hydrogen. So that from 34170 heat units must be deducted
5733, that is 34i7°-5733=28437-
This number 28437 is the available heat produced by the
combustion of hydrogen for the purpose of a gas engine. Now,
unit weight of carbonic oxide evolves 2400 heat units, and unit
volume weighs 14 times that of unit volume of hydrogen, so that
to get the relative heating effects of equal volumes of carbonic oxide
and hydrogen this difference in weight must be allowed for.
The heat evolved by unit volume of CO is therefore 2400 x 14=
33600; that is, volume for volume carbonic oxide evolves 1*18
times the heat of hydrogen. Hydrogen and carbonic oxide may
therefore be taken on an analysis of gases by volume to be nearly
equal in gas engine value. The percentage of total combustible
material may be taken roughly as representing the relative heat-
ing value of two gases : from this it appears that the French analy-
sis of Dowson gas, notwithstanding the high percentage of CO2,
represents the better gas of the two, as the English sample has
44*4 per cent, combustible and the French sample 45*9 per cent.
The French author gives the efficiency of the producer as 75 per
cent. ; that is, the gas will give 75 per cent, on combustion of the
total heat which the original fuel would have given. If it were
certain that the analysis represented the composition of the gas as
it left the producer, then the efficiency could be calculated from the
analysis itself ; but as the gases pass through scrubbers and coolers
before reaching the gas holder, and thereby lose carbonic acid and
water vapour, it is impossible to calculate the efficiency of the
producer with accuracy from the analysis.
Dowson gas of the composition given at page 363 requires for
the complete combustion of i cb. ft. as nearly as possible 0*24
cb. ft. of oxygen or 1-13 cb. ft. of atmospheric air; that is,
Dowson gas requires for its combustion a little more than its own
366 The Gas Engine
volume of air. From Table III. in Appendix II. it will be seen
that in samples of illuminating coal gas from twenty different gas
works in Britain the proportion of air required for complete
combustion varied from 5*19 vols. to 7^40 vols. of air; that is,
i cb. ft. of coal gas required in one town only 5-19 cb. ft. of air
for its combustion, while i cb. ft. of the gas of another town
required 7*40 cb. ft. of air.
The heat evolved by T cb. ft. of Dowson gas is about one-
fourth of that evolved by an average gas, such as Birmingham gas,.
so that the amount required in a gas engine cylinder is about
four times what would have been required with coal gas. For a
gas admitted to the cylinder in the proportion of i of coal gas to
8 of mixture of gas and air, it would require 4 of Dowson gas, but
this would leave too little air for combustion. Consequently till
very recently the diagram obtained in a gas engine cylinder from
Dowson gas did not give so high an average pressure as coal gas.
In ordinary practice, according to the author's experience, it was
not safe to rely on an average available pressure of more than
50 Ibs. per sq. in., while coal gas easily gave 70 Ibs. By using>
however, Messrs. Crossley and Atkinson's new scavenging engine,
enough air can be introduced to burn a larger quantity of Dowson
gas, so that now an average available pressure of 65 Ibs. per
sq. in. can be relied upon in such an engine using Dowson gas
and giving about 40 I HP ; in larger engines higher available
pressures may be obtained, and in smaller engines lower
pressures.
To secure the good and economical working of a gas engine
it is absolutely necessary that the gas supplied to it should be of
fairly uniform quality, otherwise the engine, which is adjusted to
draw in gas and air in a fixed proportion, may at one moment
be taking in a gas of such richness that the air allowed is in-
sufficient for combustion, and at another time the gas may be so
poor that the air is too largely in excess, and so a weak explosion
or no explosion at all is obtained.
One of the advantages of a fixed carbon fuel, such as anthracite
or coke, with little or no volatile matter, is that when such fuel is
added to the generator no gases are given off by destructive
distillation. In the Dowson generator, fig. 171, if such gases were
The Production of Gas for Motive Power 367
given off at each charging with fuel, then they would find their way
direct into the gasometer and practically fill the gasometer with
gases such as CH4, C2H4 and pure H to such an extent as to
render the gas much too rich to be burned in the gas engine
cylinder with the proportion of air allowed for the ordinary
Dowson gas. The addition of anthracite or coke produces no
such disturbance ; further the composition of the incandescent
charge in the generator remains fairly constant until it is wholly
consumed, so that there is no variation from that cause. Again, if
ordinary flaming coal be added to the producer, large quantities
of condensible carbon compounds, such as tar, would be given off,,
and the scrubbing and purifying would be much more difficult.
Altogether the Dowson apparatus, although it solves the problem
in an easy and practical manner, limiting its fuel to anthracite and
coke, does not do so for the cheaper but more troublesome fuels
used under the ordinary steam boiler. The percentage of heat
obtained, however, from the gas generated, 75 per cent, of the
original heat of the fuel, compares satisfactorily with the
efficiency of an ordinary Lancashire steam boiler without
economisers.
Lencauchez Gas Producer. — The Lencauchez producer is not
to the author's knowledge in use in England, but it is reported
favourably upon by Professor A. Witz and others in France. It
is an attempt to improve upon Dowson's producer in such manner
as to save some of the heat at present lost with the highly heated
gases leaving the producer, to get back in fact some of the heat
which at present is entirely lost by cooling the gas ; and further
to make . such producers suitable for use with fuel, such as
slack or other fuel giving off considerable quantities of volatile
carbon.
Fig. 174 is a vertical side section, and fig. 175 is a front
elevation part in section of this producer. A is the gas generator
lined with fire brick, B is the grate and c the closed ash pit, D is
the feed hopper with upper and lower door or valves, E is a bridge
passing down from above and causing the gas to flow from about
the middle of the producer instead of from the top, F is the gas
discharge passage, which first passes up through the brickwork and
then passes up a flue or tube formed through two cylindrical
The Gas Engine
FIG. 175.
FIG. 174. — Lencauchez Gas Producer (vertical side section).
FIG. 175. — Lencauchez Gas Producer (front elevation, part section).
The Production of Gas for Motive Power 369
vessels or chambers respectively G and H. The lower vessel G is
an air and steam heater, the upper is a boiler. From the upper
vessel the gas passes to the gas holder by the pipe I ; K is a valve
at the top of the branch to allow the gas to be ignited and sampled
at any time either at starting or during operation. The action is
as follows : The generator is started much in the same way as
has been described for Dowson, but the hot gases ascending the
tube or passage F heat the vessels G and H, steam is formed in H,
but without pressure, and it flows into the casing G by way of the
pipe H1 : air is forced into the casing G from the pipe L by means
of a fan or other positive blower, it mixes with the steam proceed-
ing from the upper vessel and both are considerably heated, the
air then flows by the pipe M shown in dotted lines to the closed
ash pit c. The heated mixture of air and steam passes through
the incandescent fuel in the generator, forms carbonic oxide and
hydrogen and passes up the passage F. The fuel meantime which
is in the upper part of the generator A is by the heat from below
being subjected to destructive distillation, and the gases formed,
as they cannot escape by the hopper, pass down through the
incandescent fuel and then escape by the passage F with the other
gases. This descent through the incandescent fuel is stated to
have the effect of splitting up all the tarry matters contained in
the volatile gases and fixing the gases in permanent form as CH4,
C2H4 and H. The fuel does not reach the incandescent part
until it is thoroughly coked. By this arrangement of separating
the freshly charged fuel from the incandescent fuel and passing
the hot gases away from a part of the generator which contains
nothing but incandescent fuel, it is stated that the difficulty of
using fuels such as common slack is avoided.
The producer is ingenious and worthy of careful study, but
the author is of opinion that with such fuel it will be found that
the system of destroying the tar and coking the fresh fuel is not
sufficiently perfect, and that dirtier gas of irregular composition
will be fed to the engine. With anthracite or coke, however, the
Lencauchez producer will work well and give some economy over
the Dowson.
According to Richards this producer with French anthracite
gives gas of the following composition :
B B
370 The Gas Engine
ANALYSIS OF LENCAUCHEZ GAS (ANTHRACITE).
Nitrogen, N . . .- . . 47*84
Carbonic oxide, CO . . . 27*32 \
Hydrogen, H . . . i8'34 8 fi combustible.
Olefiant gas, CH4 . . . . i-asf
Hydrocarbons, C4H4 . . . i'5S/
Carbonic acid, CO% . . . 3 '60
Sulphur dioxide, SOg . . . 0*04
Sulphuretted hydrogen, H2S . o'o6
According to Richards the loss due to gasefying is only 13 per
cent. ; if this be true, then the efficiency of the producer is 87 per
cent., a higher efficiency than any standard test of a steam boiler.
The gas is considerably better than the best analysis shows Dowson
gas to be ; but the author, although he can understand some
advance in Dowson practice, cannot see that so much can be
gained by the apparatus illustrated as to increase the efficiency
from 75 percent, to 87 per cent. However, Lencauchez' apparatus
is a step in the right direction and is worthy of careful consideration.
The tar difficulty in gas producers for gas engines is a very
serious one, and even with Dowson's apparatus more tarry matter
reaches the engine than when town gas is used. This neces-
sitates frequently cleaning the valves. A very little tar getting to
the valves soon makes them work with difficulty, and so deranges
the whole action of the engine.
OtJier Gas Producers. — Several gas engine makers now manu-
facture gas producers themselves, notably Messrs. Tangyes Lim.
and Messrs. Dick, Kerr & Co. Lim., but the general principles
involved are those common to the Dowson and Lencauchez
producers, so that at present till more experience has been gained
it is needless to discuss their points of departure. Many gas pro-
ducers which are used for ordinary furnace work such as Siemens'
and Wilson's, are not applicable to gas engine work because of the
tarry nature of the gas given off and the comparative irregularity
of its composition.
Water gas, too, is sometimes stated as useful for gas engines,
but from an examination of tests with water gas plant it appears
that although the gas obtained is much richer in combustible
material, the loss in making it is greater than that with producer
The Production of Gas for Motive Power 371
gas. Water gas is produced by blowing steam upon white hot
coke, when the steam is split up, as described, into carbonic oxide
and oxygen ; after a short time the carbon loses heat, and air is
blown in to heat it up again. The gases leaving the generator in
this blowing-up process give up their heat as they leave by passing
through a regenerator, which regenerator is used to heat up the
entering steam and air on the next process. In this way gas is
obtained with but little nitrogen.
Water gas is extensively made in America for town supply, and
in this country also it is now considerably manufactured by the gas
companies to mix with ordinary coal gas.
The water gas, however, although it works a gas engine quite
well, and many gas engines in America do use it, is not interesting
from the point of view of competing with the steam boiler.
Fuel Consumption of Gas Engines with Producer Gas. —
Mr. Dowson made a test with a Crossley Otto engine of 60 HP
nominal, using his producer gas, for which he claims the very
low fuel consumption of 0762 Ib. of anthracite and coke
during a working test of eight hours. Allowing for the total loss
of fuel in the generator standing all night and also clinkering, the
consumption is only brought up to 0*873 N). Per IHP hour.
The engine was of the well-known Crossley Otto two-cylinder
type. The leading particulars of the trial are as follows :
Nominal power of engine . . . . 60 HP
Diameter of cylinders 17 ins.
Length of stroke 24 ,,
Duration of trial 8 hrs. (9.40 A.M. to 5.40 P.M.).
Total revolutions of crank shaft during trial . . 74751 = 15573 per minute.
,, explosions in left cylinder .... 25908= 53^975
,, right cylinder . . . 26619= 55'456
I 79 '9 left cylinder.
Mean available pressure on indicator diagrams . j . . ,
78 '9 average of both.
/ ^9-3 left cylinder.
Mean indicated horse power during trial . . j . rjffnt
1187
Mean temperature of gas in bags near engine . . . 67° F.
,, ,, air to engine ..... 50° F.
,, ,, water overflow from left cylinder . 125° F.
i> ,. » i> right ,, . ii9°F.
,, ,, feed water of boiler .... 75° F.
B B 2
372 The Gas Engine
Mean pressure of gas in holder . . ."". . . . . ig in water.
i, ,, steam in boiler . . ... . . 48 Ibs.
Anthracite l consumed in generator during trial .... 584 Ibs.
Coke * ,, ,, boiler to get up steam before trial . . 30 ,,
Coke consumed in boiler during trial . . . . . . 140 , ,
Anthracite consumed during trial . . .0*615 lb. per IHP working hour.
Coke ,, ,, ,, . . o'i47 ,, ,,
Total . . . 0762 ,, ,, ,,
Anthracite put in generator on morning after )
trial to make up for loss during 9 night r 0*058 ,, ,, ,,
hours . . . . . -56 Ibs. ^
Anthracite put in generator on following \
morning after raking out clinkers £c. [• 0*053 » •> »
50 Ibs. )
Total loss during night and after clinkering)
io61bs. f0'111 "
Total consumption of anthracite and coke f _
during trial and following night . . f ° 73 •> »• •>
Gas consumed 5 at rate of about 63 cubic feet per IHP per hour.
Anthracite consumed during trial, about 10 Ibs. , Per 1,000 cubic feet of
Anthracite and coke consumed during trial, about 12 Ibs. ( gas made.
Wateern4g?ned ^ C°°ling *?} 600 gallons per hour = 50-5 Ibs. per IHP per hour.
Water used for boiler . . 10 ,, ,,
Water used for cleaning gas 14 ,,
Total water used during trial 624 ,, ,, =52*4 ,, ,, ,,
Total water used for gas-making . ^2 Sallons Per x 'oo° cubic
I feet of gas made.
Oil used for cylinders during trial i£ pint at 2s. qd. per gallon.
,, ,, bearings ,, ,, . . . i£ ,, is. ^d. ,,
Coal gas 5 used for heating ignition tubes . . 4^ cubic feet per hour.
i i pair stones (4 feet diameter) 24 elevators.
Machines 13 ,, rolls (250 revolutions) 2 exhaust fans,
worked I 4 ,, disks (600 revolutions) sundry conveyors,
during I 14 ordinary silks pump,
trial. 7 centrifugal silks' shafting, &c.
' 4 purifiers.
1 Anthracite used was the usual kind from the Gwaun Cae Gurwen Colliery
Company, Limited. 2 Coke from Gas Light and Coke Company.
5 Rate of gas consumed was measured by shutting the inlet of gas holder and
timing the fall of the holder through 6 feet, while the engine was working.
4 All the water used was pumped up from the river by the engine, and run to
waste. Usually the water used for cooling an engine flows to and from an over-
head tank.
5 Coal gas was used for this purpose, because Dowson gas could not be taken
from the main supplying the engine, and there was no separate outlet from the
gas holder.
The Production of Gas for Motive Power 373
This is a valuable test as showing the best consumptions of fuel
to be obtained with Dowson gas in an engine giving off about
120 HP indicated, but it is of course lower than would be
obtained in ordinary work with the plant handled by the ordinary
engineer.
It is to be noted also that the level of fuel in the generator was
estimated as the same at the end as at the beginning of the eight hours'
test. The author considers it rather dangerous to estimate the fuel
remaining in this way ; great errors might easily creep in by this
practice. The only accurate method is to empty the generator at
the start and weigh out all the fuel for filling up and starting, then
to rake out the fuel remaining and damp it out and weigh at the
end of the test.
In 1890, Prof. A. Witz tested a Simplex gas engine of 100
HP at the Paris Exhibition, and found with Dowson gas a fuel
consumption of 1*34 Ib. of English anthracite per brake HP hour.
A recent test of an Otto engine of 100 HP with two cylinders
was made at Philadelphia by Mr. H. W. Spangler, using producer
.gas made in a producer somewhat similar to the Lencauchez under
Taylor's American patent. The efficiency of the producer was
found to be 69*1 per cent. ; that is, the gas produced by it would
produce on combustion 69*1 per cent, of the heat which could be
got by burning the original fuel put into it. The engine indicated
130 horse and consumed 1*315 Ib. of coal per IHP hour. The
coal used in the producer gave the following analysis :
ANALYSIS OF COAL USED IN SPANGLER'S TEST.
Moisture 4-20
Volatile and combustible carbon and hydrogen . . . 6-88
Fixed carbon 80-41
Ash . . 8-51
Sulphur 074
10074
This coal is evidently inferior to English anthracite, so that
the result of 1*31 Ib. per IHP is very fair. Allowing for ash
and moisture, the combustible matter burned was only 0-830 Ib.
per IHP hour.
The author tested an Otto engine recently with Dowson gas,
and found in a seven and a half hours' test a consumption of
374
The Gas Engine
1-87 Ib. of anthracite and coke per IHP. The engine indicated
23-5 horse power at 210 revolutions. Fig. 176 is a diagram
from the engine on that occasion, with the leading particulars
marked under it.
In this case, however, the author considers that better results
would have been obtained if the producer had supplied two engines
instead of one ; the consumption of anthracite in the generator,.
n200
Nominal HP, 14 ; diam. of cylinder, IT'S" ; length of stroke, 21 \" ; revs, per min.
210; fuel per IHP hour, I'Sy Ib. (anthracite and coke); indicated HP, 33*5;
BHP, 27*5 ; mean pressure, $8'4 Ibs. per sq. in. ; max. pressure, 200 Ibs. ;
pressure of compression, 83 Ibs. above atmosphere.
FIG. 176. — Crossley Otto Scavenging Engine (diagram with Dowson gas).
about half a hundredweight per hour, was too little for maximum
efficiency.
From these tests, then, it may be considered as absolutely
established that in ordinary work the consumption of anthracite
in a good Otto engine using Dowson or a similar gas ranges from
if Ib. per IHP for an engine of about 30 IHP to i Ib. for an
engine of 130 IHP.
375
CHAPTER IV.
THE PRESENT POSITION OF GAS ENGINE ECONOMY.
IN this chapter the author will discuss the fuel consumption of the
gas engine at present and the economy obtained since 1886 ; he
will examine the various causes of the advance with the object
of understanding the direction of progress, and if possible of
indicating the lines still open for improvement.
The Crossley Otto engine has made wonderful progress in
reducing gas consumption since 1886, but for the purpose of com-
parison it is desirable to go back to 1882 ; at the latter date the
Crossley engine gave an indicated horse power hour on 237 cb. ft.
of London gas of such heating power that the indicated efficiency
of the engine is £=0*17, that is 0^17 of the whole heat supplied
to the engine appears on the diagram as indicated work.
In 1888 the engine submitted by Messrs. Crossley for the
Society of Arts trials consumed 20-55 cb. ft. per I HP hour of
London gas of a heating value of 483270 ft. Ibs. per cb. ft. Cal-
culating from this and reducing the gas measurements for tempera-
ture and pressure, the indicated efficiency becomes o'2i. At the
end of the year 1888 it may be taken that the best result obtain-
able from an Otto engine of about 17 IHP was a conversion of o'2i
of the heat given to it into indicated work.
The third test taken for comparison was made by the author
at Messrs. Crossley's works, Openshaw, on August 31, 1894, on
an engine of 7 in. diameter cylinder and 15 in. stroke. This
engine developed at 200 revs, the great power of 12 brake horse
and indicated 14 horse or a consumption of 14-5 cb. ft. of Open-
shaw gas per IHP hour and 17 cb. ft. per BHP hour.
Taking the heating value of Openshaw gas as 530000 foot pounds
per cb. ft. at 17° C. and 147 Ibs. pressure, the indicated efficiency
376 The Gas Engine
is 0-25 ; that is, the engine converts 0*25 of all-the heat given to it
into indicated work. This is an extraordinarily good result, much
better, in fact, than any result ever obtained before to the author's
knowledge. To make certain that there was no mistake, the author
had the gas meter tested and the brake weights and measurements
all carefully checked in his presence.
The Messrs. Crossley have, therefore, made a very substantial
improvement in the economy of gas since 1882, and it is interesting
to note that each step of diminished gas consumption is attended
by an increase in compression ; this is very evident from the table
below.
ABSOLUTE INDICATED EFFICIENCY OF CROSSLEY OTTO ENGINES
OF SIMILAR SIZE SINCE 1882.
F ffirienrv Pressure of compression
above atmosphere
(i) 1882-88 0-17 . . 38 Ibs. per sq. in.
(2)1888-94 0-21. . 66-6 Ibs. „ „
(3) *894 0-25. . 87-5 Ibs. ,, „
The experiments giving efficiencies under (i) and (2) were
made with engines of 9 in.. diameter cylinder and 9^ in. diameter
cylinder respectively, both engines having 1 8 in. stroke, so that the
engines may be considered to be of the same dimensions so far as
change of economy due to change of dimensions is concerned. The
result (3), on the contrary, was obtained with an engine of 7 in.
diameter cylinder and 15 in. stroke, so that 0-26 would more pro-
perly represent the efficiency to be obtained from an engine of
the same dimensions as in the other experiments.
From these numbers it is evident that economy increases with
increased compression, but now the question arises : Does the
increased compression completely account for the improved per-
formance ? If the calculated result from the various compression
pressures accounts for the whole change of gas consumption
accompanying change of pressure, then it is evident that to the
increase of compression is to be credited the improved economy.
To test this the author has calculated by formula 10 on p. 53
, the theoretical efficiency of an air engine in which no practical
losses occurred, the air engine having the same proportion of com-
pression space as the actual gas engines. Those theoretical
efficiencies are shown in the table below placed beside the actual
The Present Position of Gas Engine Economy 377
efficiencies obtained in the gas engine ; a column is also given
showing the ratio between the ideal and actual efficiencies, and
other columns showing the dimensions of the engines, the gas con-
sumption per IHP hour, the ratio of compression space to volume
swept by piston, and the pressure of compression in pounds per
square inch above atmosphere.
THEORETIC INDICATED EFFICIENCY OF CROSSLEY OTTO ENGINES WITH
DIFFERENT COMPRESSIONS COMPARED WITH ACTUAL INDICATED
EFFICIENCIES WITH THE SAME COMPRESSIONS.
1
» If
J,
£ »5
n
E = calculated
efficiency for perfect
Otto cycle engines
from compression
space volume
E = actual indicated
efficiency from
diagrams and gas
consumption
Ratio of J
actual to -3
ideal £
efficiency
l!p§
1 III
a ° •" •£>
ure of comp
above atmc
consumptio
r IHP hour
•g
<J •- "
rt Q.
0
IS
ins.
ins.
Ibs.
cb. ft.
(J) 0'33
0-17
— — *=O"5"t Q'O
••a -2
18 0'6
38
24
(2) 0-40
0-21
•If
.--53 9-5
18 0-4
6i'6
20-5
(3) 0-428
0'25
•rfr^y0
15 °'34
14-8
From this table it is evident that the improved economy is
fully accounted for by the increased compression ; in every case
the actual indicated efficiency obtained from the various gas
engines is a little more than half of that which would be given by
an ideal air engine following the same cycle in a perfect manner
without loss of heat to the sides of the cylinder.
It is interesting to observe that the actual efficiency improves
somewhat more rapidly with the increase of compression than
does the thermodynamic advantage due to compression ; that
is, when the theoretical efficiency is 0*33 the actual experimental
efficiency is '33 x -51 = -17 : with theory 0*40 the actual efficiency
is '40 x *53=o<2i, while with 0*428 theory the actual is 0*428 x
•58='25.
The proportion of the theoretical efficiency actually obtained
in practice thus rises from 0*51 to 0*58. This means that with
higher compressions in addition to the thermodynamic advantage
378
The Gas Engine
due to change of cycle there is also a further advantage due
to a diminution of proportional loss of heat to the cylinder
walls.
From this it follows that very probably great further economies
are to be obtained by further increase of compression, care being
taken of course to preserve a properly shaped compression space,
that is a space having small cooling surfaces in proportion to the
volume of the compressed charge. Some of the advantage is
also due to the more rapid conversion of the heat of the explosion
into mechanical work by reason of the small space through which
a
FIG. 177. — Comparative Diagram.
Crossley Otto Engines with different compressions.
the piston moves while doing a large part of the total work of its
stroke.
To render the effect of compression readily visible to the eye
the author has drawn a diagram, fig. 177, in which the length of
the line a b represents the total capacity of the cylinder including
the compression space ; c b represent the stroke and a c the com-
pression space according to a diagram of a test taken by the
author in 1888, and d ef b is that diagram plotted down on the
scale of y^ inch equal to one pound.
The line a g represents the compression space and g b the
stroke of the Otto engine tested by the Society of Arts, while h i
The Present Position of Gas Engine Economy 379
k b is the diagram taken from the Society of Arts Report of 1888-
plotted down to the same scale as the first diagram.
The line a I represents the compression space and / b the
stroke of the engine tested by the author at Messrs. Crossley's
works, while m n o b is the diagram fig. 135, p. 316, also plotted
to yi-^ in scale.
The three diagrams are also numbered i, 2, and 3. It is quite
evident that No. 2 is larger in area than i, and that 3 is consider-
able larger than both. These diagrams show in a clear way the
great advance made by increasing compression on the indicator
diagram. Mr. Atkinson considers the improved results obtained
with the Crossley Atkinson scavenging engine to be due not to
any increase in compression, but to the displacement of the
burned gases from the cylinder, and he does not consider that
increased compression has anything to do with the increased
economy. These opinions he advanced in a paper read before
the Manchester Association of Engineers.
The author has always advocated and believed in scavenging
a cylinder by means of air, and in many of his engines he has
entirely discharged the exhaust gases by air forced in by a pump.
He has never been able, however, to credit such scavenging with
more than 5 per cent, economy as compared with the same engine
working at the same compression and retaining the exhaust gases.
The results of many tests with gas engines of the three- cycle
variety of the Otto type, in which one revolution is devoted to
replacing the whole of the exhaust gases by air, proves to demon-
stration that the gas consumption per IHP is not materially
reduced by the act of displacing the exhaust products. Such
engines have been constructed by Linford, Griffin, Barker and
others before the expiry of the Otto master patent, and although
in them the exhaust products were entirely displaced by air
they did not show a marked economy.
The matter, however, may be considered as positively deter-
mined by the experiments communicated to the author by Mr. A.
R. Bellamy, and the diagrams given at figs. 139 and 140 showing
with a compression of 60 Ibs. per sq. in. above atmosphere
a consumption of 19 cb. ft. per IHP hour, and with a com-
pression of 90 Ibs. a consumption of 17-6 cb. ft. per IHP. In
380 The Gas Engine
comparing these figures with the results obtained by the author at
Messrs. Crossley's works, it is to be remembered that Openshaw
gas is considerably greater in heating value than the gas used by
Messrs. Andrew &. Co. at Reddish. Mr. Bellamy's diagrams were
taken from the same engine with two different compression
chambers successively applied.
Scavenging by pure air has, however, great practical advantages.
The average available pressure which can be economically obtained
in the cylinder is greatly increased, and for really large engines it
is absolutely necessary to scavenge in order to avoid premature
explosions. This is especially true when high pressures of com-
pression are adopted. With such compressions premature ex-
plosions are caused by the presence of the hot burned gases,
and when these hot gases are removed by pure air the cold pure
mixture may be compressed to very high pressures without danger
of early ignition. The admission of air in the first place also
prevents any chance of igniting the incoming charge during the
charging stroke.
The author therefore considers that Messrs. Crossley &
Atkinson's new scavenging device is a most valuable invention,
inasmuch as it permits of clearing out all waste products by a
device so simple as to add no complications to the engine. It is
more valuable, however, for large engines than for small ones, as
it is much more desirable to discharge exhaust products in large
than in small engines. The invention is especially applicable to
engines using Dowson gas, and it considerably increases the
available pressure with such engines, by so increasing the air
supply present as to enable more gas to be burned economically
in the cylinder.
Figs. 178, 179 are diagrams taken from the same ' scavenging'
engine with ordinary gas and Dowson gas.
The engine has a 1 7-inch diameter cylinder and 24-inch stroke.
In fig. 178, the coal gas diagram, the power indicated is 121
horse, with an average available pressure of 113*5 IDS- per sq. in.
In fig. 179, the Dowson gas diagram, the very satisfactory avail-
able pressure of 97-4 Ibs. is obtained.
The engine is rated at 30 HP nominal.
The Dowson diagram is a great improvement on that obtained
The Present Position of Gas Engine Economy 381
with the same gas on a non-scavenging engine ; the highest
available pressure claimed by Mr. Dowson for an engine this size
is 82 Ibs. per sq. in.
Even with the scavenging device, however, it does not seem
safe to rely upon a higher pressure for anything like full load
than 65 Ibs. persq. in. with a 16 HP nominal Crossley Otto.
Methods still open to obtain increased Economy. — Modification
may still be made in the indicator diagram of the gas engine to
further increase efficiency, and the author will now discuss such
points as appear to him capable of improvement. In doing this
the author will refer to the Otto cycle, but it is to be remembered
that the impulse-every-revolution engines may be arranged to
produce any of the results brought about by the Otto engine.
The author has pointed out that the actual indicated efficiency
of a gas engine increases with the theoretic efficiency, and that
the actual efficiency varies from 0*51 to 0*58 of the theory. The
actual indicated efficiency also increases with the dimensions of
the engine, other things being similar, when the ratio of compres-
sion space, and therefore the theoretical efficiency, remains
constant. Thus at p. 377 an engine of 9^ ins. cylinder and 18
in. stroke having a theoretic efficiency of 0*40 gave a practical
indicator efficiency of 0*21 or 0-53 of the theory.
Referring to a careful test, already mentioned, of a 100 HP
double cylinder Otto engine made in Philadelphia by Mr.
H. W. Spangler, it will be found that the cylinders were each 14
in. diameter by 25 in. stroke ; the engine gave as an average 127
IHP and 92-5 brake HP at 160 revolutions per minute. The
clearance space was practically 28 per cent, of the whole cylinder
volume, that is 28 per cent, of the volume swept by piston +
compression space volume.
The theoretic efficiency of such an engine is o-4i, but the
actual efficiency was found to be 0*277, so tnat
0*277
— =o-67t;
0-41
The actual efficiency, instead of being only 0-58 of the theoretic,
rises to -675 of it, due to change in the dimensions of the engine
without practical change in the compression.
The engine mentioned on page 377 as 7 in. diameter and
382
The Gas Engine
15 in. stroke gave an efficiency of 0-25, while the larger engine
•of ii in. diameter cylinder and 21 in. stroke, having a similar
compression space, gave an efficiency of 0-275.
113-5 LBS.
FIG. 178.— Diagram, Crossley Otto Engine (coal gas).
FIG. 179.— Diagram, Crossley Otto Engine (Dowson gas).
The theoretical efficiency in both cases is 0-428, and the
ratios are
The actual efficiency, therefore, increases with the dimensions of
the engine, the compression remaining constant.
The Present Position of Gas Engine Economy 383
COMPARISON OF THE ACTUAL AND THEORETIC EFFICIENCIES
OF OTTO ENGINES OF DIFFERENT DIMENSIONS.
Engine cylinder
Relative
capacity
Ratio of ac-
tual and ideal
efficiency
XT , i 17'' diam. x ie." stroke .
Nearly equal _j '
compression /
v n-£" diam. x 21" stroke
I
377
•428
•428
•25
•275
— 5='58
•428
Nearly equal] 9?'' diam. xi8'' stroke
compression ]
\ 14" diam. x 25" stroke
i
2-97
•40
•21
•277
;^zz=-67
From these numbers it is evident that efficiency for equal com-
pression increases considerably with the dimensions of the engine.
There is, however, a limit to this increase of efficiency with
increased dimensions.
The increase in the efficiency of the larger engines as compared
with the smaller using the same proportion of compression space
is due to the diminished proportional loss of heat from the gases
of the explosion to the inclosing metal walls, and it is always found
that in larger engines the expansion curve tends more and more
to rise above the adiabatic line. With a maximum temperature
of explosion of about 1600° C. it is found by experiment that
the actual increase of temperature due to explosion accounts for
about from 0*6 to 07 of the total heat of the gas present ; there
is therefore heat enough present in a gas engine of ordinary
proportions, if none be lost, to keep up the temperature during
expansion performing work to the maximum 1600° during the
whole expansion stroke. The increase in dimension if carried
to an extreme could therefore only reduce the loss to insignificant
relative proportions, and in such a case the mass of incandescent
gas might be considered to lose no heat whatever to the walls of
the cylinder.*
Assume an air engine in such a case ; the total volume of
the stroke plus clearance space being i cb. ft.
Assume the engine to have a compression space of 0-275 °f
the whole cylinder volume, as in the test made by the author on
Crossley's Otto scavenging engine, page 316. Then the diagram
384
The Gas Engine
and results would be as shown in fig. 180, where the temperature
of explosion is 1600° C.
From this it will be seen that while 0-409 is the efficiency
for adiabatic expansion, then 0-346 is the efficiency for isothermal
expansion ; from this, then, it appears that, allowing for the known
property of the suppression of heat in a gaseous explosion, the
330
300
250
200
100
60
00
+0
20
ol
Efficiency of adiabatic compression and expansion = 0*409.
Efficiency of adiabatic compression and isothermal expansion =0*346.
FIG. 1 80.— Theoretical Diagram,
comparing adiabatic and isothermal expansion.
utmost efficiency possible for an engine using coal gas, having
a compression space of 0-275 °f the total cylinder volume, and
expanding to the same volume as existed before compression,
is 0-346, so that the efficiency actually attained in practice is
— ZZ=o"8o or 80 per cent, of the possible.
34^
So far, then, practice has shown that the absolute efficiency of
the gas engine has been increased from 17 per cent, in 1882 to
practically 28 per cent, in 1895, that is from converting 17 percent,
of the whole heat into indicated work to 28 per cent, of the whole
The Present Position of Gas Engine Economy 385
heat, and this great change in economy has been brought about
by increase in compression alone. The compression pressure
has risen from 35 Ibs. per sq. in. above atmosphere to 90 Ibs.
per sq. in.
The question now arises, How far can this compression be still
enhanced? It will be observed from the formula 10 on page
53 that the efficiency increases somewhat slowly at the higher
pressures, and thus a limit must be reached beyond which the
increasing weight and dimensions of the engine parts due to rising
maximum pressure will more than compensate for the improved
theoretical economy.
Assume, for example, that a compression of 210 Ibs. per sq. in.
above atmosphere is feasible ; the volume of the compression
space will then be 0-144 of the total cylinder volume, so that the
theoretic efficiency of such an engine will be
,0-408
The ideal efficiencies for different compressions thus stand :
E=o-33 for 38 Ibs. per sq. in. compression above atmosphere.
E = o'40 ,, 66'6 ,, ,, ,, ,, ,,
£ = 0-428 ,, 87-5 ,,
£ = 0*546 ,, 2IO ,, ,, ,, ,, ,,
Such a compression as 210 Ibs. per sq. in. above atmosphere
would produce with an explosion temperature of 1600° C.
a maximum pressure of 675 Ibs. per sq. in. above atmosphere,
and this would involve an engine of nearly double the weight
of working parts as compared with the engine tested by tfye
author at Messrs. Crossley's, with but a small increase in power
for the great increase in weight.
The author accordingly considers a compression of 200 Ibs.
per sq. in. as considerably above the limit likely to be useful
in a simple gas engine ; to render such compressions possible
he considers that compound engines will require to be designed.
The gas engine, in the author's opinion, is now rapidly nearing
the limit of advantageous increased compression, so that no
great further economy is to be expected there.
Looking at diagram 3, fig. 177, however, it will be observed that
c c
386 The Gas Engine
at the moment of opening the exhaust valve there is still in the
cylinder a pressure of about 50 per sq. in. above atmosphere.
It is obvious that if the cylinder of that engine had been longer
and the piston could expand farther, the pressure could have
been reduced while the expanding gases were performing work in
it. This -source of economy has long been obvious to engineers,
and many, have attempted to realise it in practice. The author
has calculated an ideal case of this kind in which the pressure of
compression was 100 Ibs. per sq. in. above atmosphere, the
explosion temperature 1600°, and the (adiabatic) expansion carried
on far enough for the contents of the cylinder to fall to atmo-
spheric pressure. The theoretic efficiency of such an engine
would be 0-55, and with an engine of about 200 IHP a practical
efficiency of 0*55 x *6 = '33 is probable.
In the author's opinion efficiencies of 35 per cent, of the
whole heat given to the engine are now within the reach of the
engineer.
The question, however, as to whether greater or less expansion
should be utilised in an engine is altogether a matter of dimen-
sions ; for small engines great expansion beyond the volume of
the charge before compression is inadvisable, as the reduction of
the volume of mixture dealt with at each stroke may readily so far
increase the relative loss of heat to the cylinder as to more than '
neutralise the gain obtained from the extra expansion.
In very large gas engines it will be undoubtedly advisable
to adopt the compound principle, and many engineers have
attempted compounding ; so far, however, compounding is not
successful. Otto, Clerk, Atkinson, Crossley, Burt, Dick, Kerr &
Co. and others have attempted compounding, but the principles
involved are not yet thoroughly understood and require further
investigation.
One important point, however, is clearly established by Burt's
engine, figs. 156, 157, and 158, that flame gases do not lose much,
heat when passed from cylinder to cylinder by short open ports.
Experiments made by the author also bear this out. Compound-
ing to be successful must be carried out by means of very short
straight and unobstructed ports.
PART III.
OIL ENGINES.
CHAPTER I.
PETROLEUM AND PARAFFIN OILS.
-OiL engines resemble gas engines in this, that the power is gene-
rated by the explosion of a compressed inflammable gaseous
mixture in an engine operating according to the well-known Otto
cycle.
In the older gas engine patents it was customary to assume
that a gas engine was necessarily an oil engine also, and that only
trifling additions or modifications were required in order to con-
vert any gas engine into an oil or inflammable vapour engine.
For many years, however, the difficulty of using safe oil and
producing compressed explosive mixtures from it was so great that
no effective oil engine was placed upon the market. Even now
the oil engine is a much more tricky machine than the gas engine,
although it is more reliable than was formerly the case, and it is
rapidly settling down by the industry and experiments of many
inventors to something like a standard type.
In the earlier oil engines very light inflammable oils of the
gasoline kind were used to supply the engine with inflammable
vapour, and in these the problem of vaporising the oil was com-
paratively simple. It was only necessary to draw air over a surface
saturated with gasoline or some lighter oil, to produce a mixture
of inflammable vapour and air, which when taken into the cylinder
of a gas engine readily supplied the place of the ordinary coal
gas, and gave explosions under compression closely resembling
those obtained with coal gas. The legal restrictions placed upon
c c 2
388 Oil Engines
the carriage and storage of such light oils, however, made it
impossible for engines using only such oils to be applied exten-
sively in this country, and accordingly it became necessary to
devise engines with vaporisers of a kind capable of supplying
inflammable vapours of gases to an engine using oil such as is
commonly adopted for petroleum or paraffin lamps. Such oils are
much less volatile than the gasoline oils already mentioned, and
accordingly it is much more difficult to produce from them
inflammable vapours capable of exploding in a gas engine
cylinder.
The object of the engineer in dealing with those heavier oils
is to so treat them as to charge the engine cylinder with an
inflammable mixture of air, and the particular hydrocarbon, which
mixture is sufficiently stable in the gaseous or vapour state to stand
compression without liquefaction. At the same time the explosion
obtained should be powerful and regular, and the combustion so
complete as to avoid deposits capable of clogging the valves and
working parts.
Many difficulties have been found in so vaporising oils as to
produce a suitable inflammable mixture, and at the same time
avoid clogging up the vaporiser or the engine.
A knowledge of the properties of the principal hydrocarbons
used will assist the engineer in deciding between differing methods
of procedure, and accordingly the author will now describe and
discuss the properties of the various hydrocarbon oils from the
point of view of the oil engine inventor or designer.
Chemistry of Petroleum and Paraffin Oils. — A few words will
first be necessary, however, on the chemistry of petroleum and
paraffin. The oils used for petroleum engine purposes consist
mainly of three varieties — American petroleum, Russian petroleum,
and Scotch paraffin oil.
The American and Russian petroleum is obtained by refining
crude oil which issues from oil wells found in the United States
of America, and in Russia on the shores of the Caspian Sea.
Crude petroleum, as it issues from the wells, is a mixture of
many different substances, some gaseous, some liquid, and some
solid ; the crude petroleum is, in fact, a liquid containing various
gases in solution, and various solid bodies as well The various
Petroleum and Paraffin Oils 389
liquids, solids and gases, however, resemble each other in one
particular. They are every one of them hydrocarbons, that is
chemical compounds of which hydrogen and carbon are the sole
constituents.
American petroleum consists principally of hydrocarbons be-
longing to a chemical series known as the paraffin series. This
series has the general formula CnH2n+2. Members of another
chemical series, however, are mixed with the paraffin group.
This other series is known as the olefine series, and the general
formula is CnH2n.
Both the paraffin and the olefine series comprise substances
ranging from the gaseous state to the solid state ; that is, each series
contains substances which are solid, substances which are liquid,
and substances which are gaseous.
The lightest member of the paraffin series is the well-known
marsh gas methane (CH4), and one of the heaviest of the liquid
products is known as pentadecane, C15H32, and the solid paraffin
so well known in commerce in the form of paraffin candles is a
mixture consisting principally of solid members of the paraffin series,
together with some solid members of the olefine series. The
olefine series likewise comprises a whole range of compounds
beginning with the well-known gas ethylene (olefiant gas), and
terminating with solid olefines containing more than 20 equi-
valents of carbon to 40 equivalents of hydrogen.
Crude Pennsylvania petroleum as it issues from the wells
gives off as gases :
Methane (Marsh Gas) . . . . . C H4
Ethane C2H6
. Propane C3H8
and 12 separate hydrocarbons of the paraffin series have been
isolated from the crude liquid. These twelve hydrocarbons are
given in the table on page 390 with formulae, specific gravity, and
boiling point of each.
All these hydrocarbons, except the first, are liquid at ordinary
temperatures. The boiling points of the hydrocarbons vary from
o° C. to 260° C., and the specific gravity from '65 to 792.
It will be observed that in every one of these compounds the
hydrogen atoms going to form the molecule are double the
390
Oil Engines
number of the carbon atoms, plus an additional two hydrogen
atoms. Marsh gas, for example, has in the molecule i atom car-
bon, and 2 atoms hydrogen + 2. Ethane has 2 atoms carbon,
and 4 ^toms hydrogen + 2, that is 6. The same proportion is
given in all the members of the series in the table.
SOME HYDROCARBONS OF THE PARAFFIN SERIES
FOUND IN PENNSYLVANIA PETROLEUM. (REDWOOD.)
Name
Formula
Specific Gravity
Boiling Point
Normal
Normal I so.
Butarie ....
C-iHu)
0-645 at o° C.
o°C.
Pentane
CsH12
0-645 .. o° C.
38° C. 30° C.
Hexane ....
CeH14
0-63 „ 17° C.
fc9° C. 61° C.
Heptane
C7H16
0712 „ 16° C.
98° C. 91° C.
Octane ....
QHis
0726
124° C. 118° C.
Boiling Point
Nonane.
Q? H-20
071 at 15° C.
136° to 138° C.
Decane . .
C10H22
0757 .- 15° C.
160° , 162° C.
Endecane
Dodecane
CnHo4
. C12H26
0765 ,, 16° C.
0766 ,, 20° C.
180° , 184° C.
196° , 200° C.
Tridecane
C15H28
0792 „ 20° C.
216° , 218° C.
Tetradecane .
Ci^rl^o
236° , 240° C.
Pentadecane .
C 13^33
255° , 260° C.
Pentadecane, the highest here shown, has 15 atoms carbon
associated with 30 + 2 atoms of hydrogen.
The hydrocarbons of this series resemble each other very
much in chemical and physical properties. They decompose
under the action of heat in a similar manner, and they have
similar physical properties. Chemists call such a series of com-
pounds a homologous series.
The American refined lamp oils of commerce consist prin-
cipally of the heavier hydrocarbons given in the list, but they also
contain in smaller quantity hydrocarbons of the olefine series.
The table on page 391 gives a few of the best known mem-
bers of this series.
These compounds form what chemists call an isomeric series,
because, as will be observed, they are all of the same percentage
composition. Each hydrocarbon of the series contains exactly
the same proportion of hydrogen and carb6n, namely, 857 carbon
to 14*3 hydrogen. The compounds, however, differ in molecular
density, and this is found by the increasing vapour density ;
Petroleum and Paraffin Oils 391
thus, if one volume of ethylene be taken as the unit of weight,
an equal volume of butylene weighs 2, hexylene 3, and so on.
SOME MEMBERS OF THE OLEFINE SERIES.
Boiling Point Specific Gravity
Ethylene (Olefiant Gas) . . C2H4 . . Gaseous
Propylene .... C3H6
Butylene . -' . . . . C4H8 . . 4° C.
Amylene . . . . . C5H10 . . 73° C.
Hexylene. . . . . C6H12 . . 70° C.
Heptylene ... . C7H14 . . 84° C. . . 0714 at o° C.
Octylene . ' . . . . C8H16 . . 119° C.
Diamylene ". C10H20 • • 165° C. . . 0777 at o° C.
Triamylene . . . ; C15H30 . . 248° C.
Tetramylene . . . . C20H40 . above 390° C.
The term isomer is sometimes limited to compounds of the
same molecular density as well as the same percentage composi-
tion. Such compounds, however, differ in physical and chemical
properties.
At first it is very surprising to find that two chemical substances
of identical chemical composition and molecular density, that is,
with the exact proportions of the element present, the same in
both, should have different properties, but the case is strictly
analogous to what is known of the elements. Many chemical
elements are known to exist in several forms, without change of
chemical composition. Carbon exists, for example, in three forms,
the diamond, graphite, and charcoal. These three forms are
widely different in appearance and physical properties, but each
contains nothing but carbon, and produces nothing but carbonic
acid on burning.
Phosphorus also exists in two forms, yellow and red, and it
is more than suspected that iron exists in several forms.
When elements vary in this way, the variations from the best
known form are called allotropes or allotropic modifications.
When a chemical compound has several varieties, the variations
are known as isomers. The word isomer, however, is more strictly
used to denote compounds not only of the same percentage
composition, but of the same molecular weight.
Bodies of the same percentage composition and different
392 Oil Engines
molecular weights are known as polymers. The olefine series
then are polymers.
The defines are present in American petroleum to only a
small extent, but in Russian petroleum they form the principal
constituents. The hydrocarbons present in Russian petroleum
are not quite the same as the normal defines, but appear to be
isomeric modifications of the true olefine series, having the
general form of CnH2n_6H6. This formula seems to be a round-
about way of expressing the same thing as CnH2n, because 6H is
deducted, and 6H added. It is not, however, the same form as
CnH2n, but expresses chemical relationship to another set of com-
pounds. The compounds of the general form CnH2n-6H6 are
called naphthenes, and the naphthenes, although of the same per-
centage composition as the olefines, resemble the paraffins more
closely in their chemical decompositions. The naphthenes, which
have been isolated from Russian petroleums, are according to
Redmond as follows :
NAPHTHENES ISOLATED FROM RUSSIAN PETROLEUM.
C8H16 . . . 119° C. QoHot . . . 196° C.
C9H18 . . . 136° C. C14H28 . . . 240° C.
C10H20 . . . 161° C. C15H50 . . . 247° C.
CnH22 . . . i8o°C.
The specific gravity of the first-mentioned hydrocarbon
octonaphthene, C8H16, at o° C. is 7714, and that of dodeca-
naphthene at 17° C. is -8027.
Paraffin oil, as its name implies, is mostly composed of
members of the paraffin series, and it is produced by the destruc-
tive distillation of Scottish shale. The crude oil obtained from
the retorts contains, like petroleum, substances both solid, liquid,
and gaseous. The solid paraffin of commerce is generally obtained
trom this paraffin oil.
The chemistry of petroleum and paraffin oils is extremely
complex, and only a general idea has been here given of the main
constituents.
Before leaving the chemistry, it is desirable to consider the
decompositions of these compounds by heat. It is found, for
example, that if a heavy member of the paraffin series be exposed
to heat under pressure, so as to attain a temperature higher than
Petroleum and Paraffin Oils 393
the boiling point, then that compound decomposes into a lower
paraffin and an olefine. The paraffin hydrocarbon C12H26, for
example, may be decomposed into hexylene C6H]2, and hexane
C6H14. The reaction may be taken as follows :
The heavier hydrocarbon thus splits up into a paraffin and an
ethylene containing a smaller number of carbon and hydrogen
equivalents to the molecule. It depends entirely, however, on
the particular temperature and treatment as to the actual decom-
position which will take place. If the temperature of the hydro-
carbon be raised to a high enough point, marsh gas, CH4, can be
produced, and carbon left in the retort. The defines decompose
also, heavier defines producing lighter defines by the influence
of heat, or lighter defines together with hydrogen, marsh gas, and
solid carbon deposit.
Petroleum Ether and Spirit. — The volatile liquids produced
from American petroleum have been classed as petroleum ether
and petroleum spirit. The following table gives a list of the
substances so produced. The names given are not chemical
names, but ordinary trade names, and the compounds are not
pure hydrocarbons of one composition, but mixtures of hydro-
carbons boiling at very low points.
PETROLEUM ETHER AND SPIRIT.
Specific Gravity
Petroleum Ether .
Petroleum Spirit
/i. Cymogene ....
\ -2. Rhizoline
(3. Gasoline .....
/4. C Naphtha (Benzine Naphtha) .
\ 5. B Naphtha ....
1 6. A Naphtha (Benzine) .
•590
'625 to '631
•635,, "666
•678 ,, 700
714,, 718
741,, 745
According to Mr. Alfred H. Allen, cymogene consists chiefly
of butane, C4H10, of pentane, C5H12, and an isomer of that
substance ; and hexylene, C6H12, and an isomer of hexylene.
As these products are extremely volatile, cymogene boiling at
o° C., the freezing point of water, and the heaviest A naphtha
boiling away under 70° C., it follows that they are dangerous to
handle, and are far too inflammable for general use in oil engines.
394 Oil Engines
The substance cymogene, for example, could only be retained in
the liquid state permanently by means of a freezing mixture, and
all the others are so volatile that it would be dangerous to
approach an open vessel containing them with a light. Any one
of these liquids would go on fire instantaneously on plunging a
lighted match or taper into the liquid. Liquid so inflammable
and so capable of producing large volumes of explosive mixture
are much too dangerous for successful use by the general public
in engines.
The whole of these liquids are clear limpid fluids, having
when pure a rather agreeable odour.
Petroleum and Paraffin burning Oils sold in Britain. — The
oils which really concern the "engineer designing petroleum
engines are not the crude oils or the petroleum spirit or ether,
but the burning oils which are sold in Britain in a condition
sufficiently safe to be used in ordinary lamps. The Petroleum
Act of 1876, and its subsequent modification in 1879, determines,
that oils sold for illuminating purposes shall not have a flashing
point less than 73° F., the flashing point to be determined by a
special apparatus fully described in the Act. The apparatus and
the method of manipulating it are the work of Sir Frederic
Abel, so that the- standard test for these oils for flashing point is
known as the Abel test.
Fig. 181 is a section of the Abel close test apparatus, from
which it will be seen that a copper vessel c is provided which
contains water marked w. This water forms a water bath. An
air chamber A is placed within the water bath, and it carries
within it an oil cup p made of gun metal. This cup rests upon an
ebonite ring, and over the air chamber A, and has a tight-fitting lid
on which is fixed a gas burner. The oil cup carries a thermo-
meter /, and above the cover is fixed a slide, which slide on
being moved is caused to uncover three holes. The gas jet
swivelling on a lever, and moving with the movement of the
slide, carries a small flame, and the movement is so combined
that, as the lever tilts, the flame is passed through one of the
openings in the slide and reaches the top of the oil in the oil
cup.
The thermometer f is intended to take the temperature of the
Petroleum and Paraffin Oils
395
water bath, and the spirit lamp b supplies the necessary heat.
The pendulum shown alongside of the apparatus is 24 inches
long, and is intended to time the operation of testing the flash.
To determine the flashing point of the oil, the temperature of
the water bath at the start of the test is arranged at exactly 130° F.
The oil to be tested is cooled to 60° F. and poured carefully into
the oil cup P, avoiding splashing, until the oil reaches the point of
a small bent wire gauge inside the cup. The lid is then put on,
and the cup placed in the bath, the rise of the temperature being
FIG. 181.— Abel Flash Test Apparatus.
watched on the thermometer / in the petroleum cup. When the
oil reaches the temperature of 66° F. the testing is started by
setting the pendulum in motion, and while it makes three oscilla-
tions, drawing the slide slowly open, and at the fourth oscillation
closing . it rapidly. By this the test flame is gently tilted through
a hole in the slide to the space above the oil. This operation is
repeated once for every increase of temperature of i° F. until the
vapour of the oil ignites within the oil cup, giving a pale blue
flicker or flash. The temperature of the oil at which this occurs
is called the flashing point ; that is, the flashing point is that
396 Oil Engines
temperature at which the oil gives off sufficient vapour to be
ignited by a flame. The lowest flashing point allowed by law for
petroleum intended for burning lamps in this country is 73° F. or
22-8° C. It is very important, therefore, in experimenting upon
various samples of oil, to make certain that the oil is above the
legal flashing point.
Other qualities are also necessary, and these can be determined
by the specific gravity of the oil, and by the distillation of the oil,
and observation as to the range of temperature during which the
oil boils over.
The ordinary burning oils sold in Britain are American oils,
.Royal Daylight, Ordinary, Water White, and Tea Rose.
The Russian oils are Russoline and Russian Lustre.
The paraffin oils are Broxbourne Lighthouse, Young's paraffin
oil, and similar oils by many other makers.
Professor Robinson has made an interesting series of experi-
ments upon the principal burning oils sold in Britain, and he has
determined the specific gravity flashing point by Abel's test, the
point at which each oil begins to boil, and the. percentage distilled
between certain ranges of temperature. He has also made deter-
minations of the specific heat, and the co-efficients of expansions
of several of the oils.
The opposite table gives a summary of his results.
From this table it will be seen that the burning oil with the
lowest flashing point is American Ordinary, which has a light straw
colour, a specific gravity of 791, and was sold some time ago at
$\d. per gallon. This oil begins to boil at 145° C. ; at 215° C.
29 per cent, of the oil distils over to the condenser ; and at 233° C.
36 per cent, distils. To vaporise the entire oil, therefore, required
a temperature above 233° C.
Looking at the table, Royal Daylight oil begins to boil at 144°
C. ; and when the thermometer reaches 215° C. 25 per cent, of the
liquid is distilled. At 230° C. 35 per cent, is distilled. At 300° C.
Professor Robinson states in another part of his paper that 76
per cent, boils over, and at 340° C. 82 per cent. At 358° C., the
extreme limit of the thermometer used, there was still a consider-
able residue. The Royal Daylight oil, therefore, contains a very
wide range of hydrocarbons, beginning probably with octane,
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398 Oil Engines
C5H18, and certainly containing towards the end higher hydro-
carbons than pentadecane, C15H32.
Another American burning oil, Water White, having a specific
gravity of 78, has a flashing point of 108° F., begins to boil at
150° C., and at 215° C. 55 per cent, boils off.
This oil is evidently of simpler composition than the others ;
that is, it contains hydrocarbons within a smaller range of mole-
cular weight.
Russoline, it will be observed, the Russian ordinary burning
oil, begins to boil at 151° C., and by the time the temperature has
reached 221°, only 36 per cent, has boiled over. The flashing
point, therefore, of this oil is high, 82°.
Broxbourne Lighthouse oil begins to boil at about 215°, and is
completely boiled over at 300°.
From these experiments it appears that many of the burning
oils of commerce are so constituted that even at so high a tem-
perature as 350° C., part of the oil refuses to come over.
It is quite evident that the type of vaporisers required in a given
case must be largely determined by the nature of the oil. Thus an
engineer working with Broxbourne Lighthouse oil would find that
he succeeded in evaporating the whole of the oil at 300° C. by the
agency of heat alone, whereas if he had experimented with Ameri-
can Ordinary oil, he would have found at that temperature a very
large residue remaining in his vaporiser.
Methods of Vaporising and Decomposing. — Before discussing
the vaporisers in actual use, it is advisable to consider some of
the laboratory methods of vaporising, in view of the difficulty of
providing vaporisers which will treat varying oils of high flashing
point and density.
When a homogeneous substance like water is boiled, the tem-
perature remains constant from the moment of boiling to the com-
plete distillation of the whole liquid.
Likewise if dry air be blown through water, every cubic foot of
air will carry off a certain volume of water vapour, until the whole
of the water is evaporated, and this will occur by blowing through
air at any temperature at which water has an appreciable vapour
tension.
The vapour tension of water is the pressure of water vapour at
Petroleum and Paraffin Oils 399
any given temperature. The term vapour tension is generally used
for pressures under atmospheric pressure.
The following table gives the vapour tension of water for
different temperatures from o° C. to 100° C. The tension is given
in millimetres mercury ; that is, the tension of the water vapour at
each temperature is given in the height of mercury column which
the particular pressure of water vapour at that temperature is cap-
able of supporting.
VAPOUR TENSION OF WATER VAPOUR.
Tension Tension
Temp. C. mm. Mercury Temp. C. mm. Mercury
4'6
5° 5'53
10° ... 9-17
15° ... 1270
20
30°
23 '55
40° . . . 54-9I
50° . . • . 91-98
60° . :. . 14870
70° . . . 233-09
80° . . . 288-51
90° .... 525-45
100° . . . 760*00
From this table it will be observed that at 15° C., about the
ordinary temperature of the atmosphere, the tension or pressure of
water vapour is equal to 127 mm. mercury. The total pressure
of the atmosphere is taken as 760 mm. mercury, from which it
would appear that the pressure of water vapour at that temperature
is about -^ of the pressure of the atmosphere, so that if water were
to be evaporated by passing air through it at that temperature,
60 cb. ft. would require to be passed through to take away i cb. ft.
of water vapour, that is to take away a volume of vapour sufficient
to make i cb. ft. of steam supposed to be at atmospheric pressure
and temperature. If, however, the temperature be raised to about
80° C., 2 cb. ft. of dry air would carry away about i cb. ft. of steam
calculated at atmospheric pressure.
Water can thus be evaporated either by boiling it off by raising
the temperature above the boiling point, or by passing air through
it or any other gas at a temperature below the boiling point ; and
the amount carried off by a cubic foot of air depends upon the
temperature of the water.
The important point to remember is, that to however low a
temperature the water be reduced, it can be entirely evaporated
by treatment with a sufficient volume of air.
400 Oil Engines
Petroleum or oil in the same way can be evaporated either by
boiling off, or by treatment with air or gas ; and the temperature
at which the whole liquid can be evaporated is much reduced by
passing hot air over the liquid, instead of attempting to boil the
liquid away. Thus many of the American oils, which leave a con-
siderable residue at 358° C., could easily be evaporated bypassing
hot air through the liquid, without requiring any further rise of
temperature. It is often objectionable to attempt to vaporise by
boiling off or distilling, because in many oils the boiling point is
so high that the decomposition point is reached before the liquid
will boil. In such a case, attempting to force vaporisation or dis-
tillation by increasing the heat only results in the chemical decom-
position of the oil, and leaving in the vaporiser a comparatively
large quantity of carbon or tar. A sample, for example, of solid
paraffin, such as is used for candles, could not be entirely distilled
by any attempt at boiling ; but if the sample be placed in a vessel,
which vessel is heated to the highest temperature which the paraffin
will stand without decomposition on a sand bath — say about
400° C. — and super-heated steam be blown through the liquid
paraffin, then nearly the whole of that solid paraffin can be distilled
without decomposition. From this it follows that, if vaporisation
is desired without decomposition, the temperature can be kept
much lower by heating the vaporiser to a predetermined point,
and then passing hot air over the liquid contained in it.
It is interesting to note, in connection with the decomposition
of paraffin and olefines by heat, that mere heating up in a closed
vessel does not produce any large amount of decomposition. If,
however, the oil or paraffin be heated up under pressure in such
manner that the ordinary boiling point is considerably exceeded,
and that oil be distilled and condensed in a condenser — also
under pressure — then the oil rapidly decomposes.
Some well-known laboratory methods of experimenting illus-
trate in a vivid manner the various facts which are useful to the
engineer designing oil engines. The distillation of water, for
example, in the laboratory apparatus shown in fig. 182, and the
subsequent distillation of oils in the same apparatus, enables one
to realise the difference between the nature of oils and water.
The apparatus is very simple, and consists of a glass flask A
Petroleum and Paraffin Oils
401
having a tightly fitting cork «, through which passes a glass T piece
£, carrying the thermometer B. The free end of the T piece slips
into the glass condenser tube c. This condenser tube passes
within a water jacket tube D, fed with a current of cold water by
the side tube c, which current discharges at d. The condenser
tube terminates in the glass receiving flask E, supported upon a
retort stand ; the condenser is held by a clamp, also supported on
a retort stand, and the distilling flask rests upon wire gauze sup-
ported on a tripod, and is heated by a Bunsen flame.
It is an interesting exercise to rig up this apparatus, and distil
fresh water from the flask, observing the thermometer during the
•B
FIG. 182.— Distillation of Water.
process. Fresh water will boil away to the last drop, and collect
in the receiving flask while the thermometer remains steady at
100° C. from the beginning of the boiling to the completion of
the distillation.
If a sample of Royal Daylight oil be placed in the distilling
flask (carefully dried from water), it will be found that the oil
begins to boil about 144° C., and that a lighter oil first passes over,
and that the thermometer slowly rises, so that at 340° C. only
82 per cent, of the whole had distilled over, and even at 358° C,
a considerable liquid residue was left in the vessel. If the receiving
flask be frequently changed in the course of the distillation, oils
of different densities will be collected, the lighter oils boiling off
D D
402
Oil Engines
first, and the heavier in order later. Such a process of distillation
is called fractional distillation, and on the manufacturing scale it
is practised to purify the oils, and separate the light from the
heavy. In making this experiment with oil, the apparatus should
be modified as shown in fig. 183, where the wire gauze is replaced
by a sand bath, in order to protect the glass flask containing oil
from the direct action of the flame. In distilling oils experimentally
from glass flasks, it is well to limit the size of the flask not to
exceed 250 c.c. (quarter litre) ; and a quantity of dry sand should
be kept at hand to extinguish the oil flame if the flask breaks and
ignites.
FIG. 183.— Distillation of Oil.
It is found that as the lighter oils distil off and the thermo-
meter rises, the oil in the distilling flask gradually becomes darker
in colour, and at the high temperature of 350° C. it becomes quite
brown. At first it is of a pale straw colour, and this change to
brown proves chemical decomposition to be going on.
If a quantity of the oil which refuses to boil at even the high
temperature of 350° C. be placed in one end of a bent glass tube,
c, fig. 184, and the tube sealed up by the blowpipe flame, then
the liquid distilled from the end a into the end b without apply-
ing any cooling, but after distilling returned again to the end a
Petroleum and Paraffin Oils
403
and distilled to b again ; the process being repeated say for
about twelve times ; it will then be found on opening the glass
tube that the oil subjected to this distillation under pressure has
changed its nature very considerably. This can easily be proved
by returning it to the flask A, fig. 183, and testing the boiling
point. It is then found that the liquid which before refused to
boil at 358° C. will now begin to boil below 140° C. and the greater
part of it will distil over long before 300° C. is reached.
A sample of the same heavy oil remaining from the first oil
experiment if placed in a straight sealed tube as A, fig. 185, may
FIG. 184. — Decomposition of heavy Oil.
be heated and cooled to the same extent as and for the same time
as with the bent tube in fig. 184, and after these series of heatings
and coolings it will be found to have hardly changed its composi-
tion. These oils if merely heated under pressure without distilla-
tion can bear comparatively high temperatures without decomposi-
tion, but if distilled at the high temperature decomposition
results.
This appears due to the recombination of the oils when heated
to a high temperature and cooled slowly. For effective decom-
position it is necessary to distil.
The American petroleum refiners treat the heavy oil left in the
D D 2
404
Oil Engines
still after distilling off the light and the burning oils by a process
called cracking. The still is formed with a very large and roomy
head which causes the oil to condense and run back to the still,
and in this way after heating for a considerable time it is found that
the oil is cracked and oils of lower boiling point produced. The
cracking process, however, is attended with the separation of a
proportion of solid carbon.
Professors Boverton Redwood and Dewar have devised a
method of distilling oils in
a compressed gaseous atmo-
sphere which appears to pro-
duce more rapid and perfect
decomposition from heavier to
lighter oils.
If the thermometer be
removed from the distilling
flask, fig. 183, before the
temperature rises so high as
to damage it, and the heat be
further raised, it is found that
after a time a tarry mass is left
in the flask which cannot be
removed by heating. These
experiments very clearly show
that the particular oil could
not be vaporised by boiling off
without leaving a considerable
residue. It would, therefore,
be hopeless with this oil to
design a vaporiser to boil off the oil as vapour, it would only result
in the vaporiser being choked with tar and carbon deposit in a few
hours.
Some method is required which will vaporise the whole of
this heterogeneous oil, the heavy part as well as the light. This
can be done in another way by means of the apparatus shown in
fig. 1 86, which is the same as that shown in fig. 183 except that the
flask A has a wider neck, and the cork carries in addition to the
T piece and thermometer the air tube D. If the flask A be
FIG 185. — Heating heavy Oil
in a straight tube.
Petroleum and Paraffin Oils
405
°, then air
charged with Daylight oil and heated up to about 140
be slowly bubbled through the oil (from a gasometer), it will
be found that the whole of the oil can be distilled out of the
flask A without leaving any heavy residue, and the temperature of
the thermometer need not be raised above 200° C. In this case
almost the whole of the contents of the flask will pass over with-
out decomposition and without leaving any clogging residue or
carrying over any tarry matter.
If a sample of solid paraffin be placed in the flask fig, 186 and
heated up to about 350°, then dry steam be blown through by the
FIG. 1 86. — Distillation of Oil or Paraffin by Air or Steam.
pipe D, it will be found that even solid paraffin will distil over
practically without decomposition.
If the paraffin be heated highly alone and distillation attempted,
it rapidly decomposes, leaving a charred carbon mass.
From these experiments it is evident that the best method
of vaporising a hydrocarbon oil containing heavy as well as light
hydrocarbons is to heat the oil in a vaporiser to a moderate
temperature, say about 300° C., and then pass air over it also
heated to about the same temperature. By treating it in this
way the whole of the oil, light and heavy, can be vaporised
without fear of decomposing the oil and so producing tarry
products or carbon residues.
406 Oil Engines
It is a mistake to use red-hot surfaces in vaporising an oil
when the vapour formed has to pass through valves ; it is a
mistake, however, which inventors often make.
An oil like 'Broxbourne Lighthouse' boiling entirely below
300° C. might be treated in another way, but the method described
of passing hot air through would easily vaporise it also, so that no
other method is necessary.
The methods of distilling or boiling under reduced pressure
also supply means of vaporising oil at comparatively low tempera-
tures ; but the vacuum pan system, although largely applied to the
sugar industry, has not been applied to the vaporising of oils.
407
CHAPTER II.
OIL ENGINES.
HAVING now discussed briefly the chemical and physical properties
of the hydrocarbon oils, the reader is in a position to consider the
mechanical arrangements of oil engines. The lighter oils being so
easily vaporised were naturally first used in the early forms of oil
engine. With oils of a specific gravity less than 74 and a flashing
point as a rule lower than the ordinary atmospheric temperature
of 1 6° C., such as benzine, benzine naphtha and gasoline, the problem
of producing an inflammable mixture capable of being drawn into
an engine cylinder, compressed and exploded, is so simple that no
complicated considerations trouble the inventor in producing his
engine. The earlier oil engines accordingly used such light oils.
Early Oil Engines. — The earliest proposal to use oil as a means
of producing motive power by explosion appears to be that of
Street, whose English patent was taken out in the year 1791.
The first practical petroleum engine, however, was that of Julius
Hock of Vienna, who produced an engine in 1870. This engine
operated on the old non -compression system and took in a charge
of air and light petroleum spray during part of the forward stroke
of a piston, ignited that charge at atmospheric pressure by means
of a flame jet and so produced a low-pressure explosion similar to
that of the Lenoir gas engine. In 1873 Brayton, an American
engineer, produced an oil engine shown on p. 153 of this work. In
that engine heavy oil, it is true, was used having a density some-
times as high as '85, but this oil was crude unrefined oil flashing at
about atmospheric temperature. The engine was not a practical
success, but it was the first compression engine using oil fuel
instead of gas.
408 Oil Engines
Shortly after the Otto gas engine came into use in 1876,
several engines of that type were operated by air gas, a gas pro-
duced from the liquid known as gasoline, by drawing air through
the gasoline and so charging this air with inflammable vapour. The
air so charged was drawn into the engine cylinder with a further
supply of air and formed an explosive mixture, which was com-
pressed and ignited in the usual manner common to Otto cycle
engines.
The Spiel petroleum engine appears to be the first engine of
the Otto cycle introduced into practice which dispensed with an
independent vaporising apparatus. In this engine light oil of not
greater than 725 specific gravity was injected directly into the
cylinder on the suction stroke, and mixing with the air entering
the whole of the oil became vaporised at ordinary temperatures
or at the slightly increased temperature of the engine cylinder, and
on compression an explosive mixture was obtained which acted
precisely as the ordinary gas mixture of the Otto engine. Good
results are obtained by the Spiel engine so far as economy is
concerned, the consumption being '81 Ib. per brake HP per
hour. The engine, however, never became really popular because
such light oils as it used were dangerous, and besides legal
restrictions as to storage and transport of light oils materially
interfere with the introduction of such an engine.
Engines using safe burning Oils. — Safe burning oils having a
flashing point above 73° F. require very different treatment to
obtain an explosive mixture capable of operating an oil engine,
and the treatment required varies with the nature of each particular
sample of oil. Engines now constructed use American and Russian
petroleums and Scotch paraffin oils without difficulty. Such oils
vary in specific gravity from 78 to '825 and in flashing point
from 75° to 152° F. All of the oils in ordinary use have, as
has been already pointed out, different temperatures at which
they begin to boil at ordinary atmospheric pressure. The
temperatures vary from 144° C. to 165° C. (see table, p. 397).
Engines burning such oils may be divided into three distinct
classes :
i st. Engines in which the oil is subjected to a spraying opera-
tion before vaporising.
Oil Engines 409
2nd. Engines in which the oil is injected into the cylinder and
vaporised within the cylinder.
3rd. Engines in which the oil is vaporised in a device exter-
nal to the cylinder, and introduced into the cylinder in the state
of vapour.
This division into three classes thus refers to the mode of
vaporising. The method of ignition may also be used to divide
the engines into different classes :
i st. Oil engines igniting by the electric spark.
2nd. Oil engines ignited by incandescent tube.
3rd. Oil engines igniting by the heat of the internal surfaces of
the combustion space.
Spiel's engine was ignited by means of a flame-igniting device
similar to that used in Clerk's gas engine described on p. 2 1 5 of
this work, but Spiel's engine is the only one introduced into this
country which ever used a flame igniter. On the Continent, how-
ever, flame igniters are not uncommon. Hille's engine uses a
flame igniter. In this country, however, all methods of ignition
both in gas and oil engines have for practical purposes been dis-
placed by the hot tube and the hot surface igniters.
Engines in which the Oil is subjected to a Spraying Operation
before Vaporising. — The engines at present in use in this country
falling under this head are the Priestman and the Samuelson. In
both the oil is sprayed before being vaporised. The principle
of the spray producer used is that so well and widely known in
connection with the atomisers or spray producers used by per-
fumers. Fig. 187 shows such a spray producer in section. In
this elementary form of spray producer an air blast passing from
the small jet A crosses the top of the tube B, and creates within
that tube a partial vacuum. The liquid contained in the glass
bottle c flows up the tube B, and issuing at the top of the tube
through a small orifice is at once blown into very fine spray by
the action of the air jet. If such a scent distributor be filled
with petroleum oil such as Royal Daylight or Russoline, the oil
will also be blown into fine spray, and it will be found that this
spray can be ignited by a flame and will burn, if the jets be pro-
perly proportioned, with an intense blue non-luminous flame.
The earlier inventors often expressed the idea that an explosive
Oil Engines
mixture could be prepared without any vaporisation whatever by
simply producing an atmosphere containing inflammable liquid in
extremely small particles distributed throughout the air in such
proportion as to allow of complete combustion. The familiar
explosive combustion of lycopodium, and the disastrous explosions
caused in the exhausting rooms of flour mills by the presence of
finely divided flour in the air, have also suggested to inventors the
idea of producing explosions for power purposes from combustible
solids. Although, doubtless, explosions could be produced in that
way, yet in oil engines the production of spray is only a preliminary
to the vaporisation of the oil. If a sample of oil be sprayed in
the manner just described and injected in a hot chamber also
filled with hot air, then the
oil so sprayed will at once
pass into a state of vapour
within that chamber, al-
though the air should be at
a temperature far below the
boiling point of the oil.
The spray producer, in fact,
furnishes a ready means of
saturating any volume of air
with heavy petroleum oil to
the full extent possible from
the vapour tension of the oil
at that particular tempera-
ture. The oil engines about to be described are in reality ex-
plosion gas engines of the ordinary Otto type with special arrange-
ments to enable them to vaporise the oil to be used. The author
will, therefore, only describe such parts of the engines as are
necessary to treat the oil and to ignite it.
Priestman Oil Engine. — Fig. 188 is a vertical section through
the cylinder and vaporiser of the Priestman engine. Fig. 189
is a section on a larger scale showing the vaporising jet and the
air admission and regulation valve leading to the vaporiser.
Fig. 190 is an elevation on a smaller scale showing the general
arrangement of the engine.
In this engine oil is forced by means of air pressure from the
FIG. 187.— Perfume Spray Producer.
Oil Engines
411
reservoir A through the pipe B to the spraying nozzle c, and air
passes from the air pump D by way of the annular channel b into
the sprayer c, and there meets the oil jet issuing from a, the air
impinges upon the oil, breaks it up in spray, and the air charged
with oil spray flows into the vaporiser E, which vaporiser is
heated up in the first place on starting the engine by means of a
lamp G. In the vaporiser the oil spray becomes oil vapour
saturating the air within the hot walls, and on the out-charging
stroke of the piston the mixture passes by way of the inlet valve
FIG.. 1 88. — Priestman Oil Engine (section through vaporiser and cylinder).
H into the cylinder. The valve i allows air to flow into the
vaporiser to displace its contents, and furnish air to be further
saturated with oil spray and vapour for the next stroke. The
cylinder K is thus charged with a mixture of air and hydrocarbon
vapour, some of which may exist in the form of very fine spray.
The piston L then returns and compresses the mixture, and when
the compression is quite complete an electric spark is passed
between the points M and a compression explosion is obtained
precisely similar to that obtained in the gas engine. The piston
412
Oil Engines
moves out expanding the ignited gases, and on the return stroke
the exhaust valve N is opened and the exhaust gases are discharged
by way of the pipe o round the jacket P inclosing the vaporising
chamber. The vaporising chamber is thus kept hot by the
exhaust gases whenever the engine starts, and it remains suffi-
ciently hot without the use of the lamp G. To obtain the electric
spark a bichromate battery is used and the Ruhmkorf induction
coil. The spark is timed by contact pieces Q operated from the
eccentric rod R used to actuate the exhaust valve and the air
pump for supplying the oil chamber and the spraying jet. Fig.
189 shows the spraying nozzle on a larger scale. The oil jet
passes through the small aperture a and meets the air discharging
FIG. 189. — Priestman Oil Engine (vaporising jet and air valve).
from the annulus b by way of the re-entrant nozzle c. Very fine
spray is produced in this manner.
To start the engine the hand pump s is operated to get up a
sufficient pressure to force the oil through the spraying nozzle,
and oil spray is formed in the lamp G, and the spray and air
mixing produce a blue flame which heats the vaporiser. The
hand pump is operated until the vaporiser is sufficiently hot to-
start the engine. The fly wheel is then rotated by hand, and the
engine moves away. The eccentric shaft is operated from the
crank shaft by means of toothed wheels which reduce the speed
to one-half the revolutions of the crank shaft. The charging
inlet valve is automatic.
The Priestman engine was the first engine capable of using
Oil Engines
413
414 Oil Engines
heavy safe burning oils. It is somewhat complex in its con-
struction, and suffers under what the author considers the great
disadvantage of igniting by the electric spark, but it is the
pioneer, and the Messrs. Priestman deserve the greatest credit for
their ability and pertinacity in overcoming the formidable diffi-
culties in the way of getting an efficient explosive mixture from
heavy oils. Large numbers of the engines are in operation and
appear to give satisfaction. The sizes made by Messrs. Priestman
vary from i horse nominal to n horse nominal, and twin or
double cylinder engines have been made of 25 horse nominal.
In the Priestman engine governing is effected by throttling the
oil and air supply. For this purpose the governor operates on
the butterfly valve T and on the plug cock / connected to it, by
means of the spindle f. The air and oil are thus simultaneously
reduced, and the attempt is made to maintain the charge entering
the cylinder at a constant proportion by weight of oil and air
while reducing the total weight and therefore volume of the charge
entering. The Priestman engine therefore gives an explosion on
every second revolution under all circumstances whether the
engine be running light or loaded. The compression pressure of
the mixture before ignition is, however, steadily reduced as the
load is reduced, and at very light loads the engine is running
practically as a non-compression engine. This is a grave dis-
advantage, as the fuel consumption per I HP rises rapidly with the
reduction of compression.
Tests and Oil Consumption. — Professor Unwin made a test of
the Priestman engine at the Royal Agricultural Show at Plymouth
in 1890. The engine tested was a 4^ HP nominal, cylinder
8'5 in. diameter, 12 in. stroke, normal speed 180 revolutions per
minute. The oil used was that known as Broxbourne Light-
house, a Scotch paraffin oil produced by the destructive distillation
of shale. Its density is *8i and flashing point about 152° F.
The analysis of the oil by Mr. C. J. Wilson gave :
Carbon . . . • . • . .86*01 per cent.
Hydrogen , I3'9° »>
Deficiency . -09 ,,
loo 'oo per cent.
By calculation the heating value is 19,700 thermal units F.
Oil Engines 415
per Ib. This is the total heat evolved including heat of con-
densation of steam to the liquid state. The principal results
given by the test were as follows :
Indicated HP . . . . ... . 5-243
Brake HP 4-496
Duration of trial . .150 minutes
Mean speed (revolutions per minute) .... 179 '5
Mean available pressure (Ibs. per square inch) . . 33*96
Explosions per minute . 8975
Oil consumed per IHP per hour (Ibs.) .... 1*066
Oil consumed per brake HP per hour (Ibs.) . . . *'243
The heat account is —
Total heat shown by indicator 12*67
Heat given to jacket water . . . . . . S3 '39
Exhaust waste and other losses 33 '96
In 1892 Professor Unwin made another trial of a 5 HP Priest-
man oil engine at Hull, in the course of which he used both
Russoline oil and Daylight oil. The engine was of the same
dimensions as the Plymouth engine, that is 8*5 ins. cylinder and
12 ins. stroke. The volume swept by the piston per stroke was
•395 cubic feet, and the clearance space in the cylinder at the end
of the stroke was -210 cubic feet. The small air-compressing
pump supplying the spray producer discharged "033 cubic feet per
stroke. The total weight of the engine was 36 cwt, including a
fly-wheel of 10 cwt. The principal results obtained were as
follows :
Daylight Russoline
IHP . 9-369 . . 7-408
Brake HP 7-722 . . 6765
Mean speed (revolutions per minute) . . . 204-33 • • 2O7'73
Mean available pressure (revolutions per minute) .53-2 . .41 -38
Oil consumed per IHP per hour .... -694 Ibs. . '864 Ibs.
Oil consumed per brake HP per hour . . . -842 ,, . -946 ,,
With Daylight oil the explosion pressure was 151*4 Ibs. per
square inch above atmosphere, and with Russoline 134*3 Ibs.
The terminal pressure at the moment of opening the exhaust
valve with Daylight oil was 35-4 Ibs., and with Russoline 337 per
square inch. The compression pressure with Daylight oil was
35 Ibs., and with Russoline 27-6 Ibs. pressure above atmosphere.
4 1 6 Oil Engines
Analyses were made of the samples of Daylight and petroleum
by Mr. C. J. Wilson, F.C.S.
Daylight Russoline
Carbon . . . 84-62 per cent. . . . 85-88 per cent.
Hydrogen. . . 14-86 ,, . .. . . 14 '07 ,,
Oxygen . . • . -52 ,, . .- '. -05
loo-oo per cent. loo'oo per cent.
Specific gravity at 60° F. 7936 . . . . '8226
Flashing point . . 77° F. . . . . . 86° F.
The total heat of combustion of Daylight oil calculates out at
21,490 British thermal units, and for Russoline at 21,180 British
thermal units.
Professor Unwin calculates the amount of heat accounted for
by the indicator as i8'8 per cent, in the case of Daylight oil, and
15*2 in the case of Russoline oil. Fig. 191 is a diagram taken by
Professor Unwin, and published in his paper read before the
Institution of Civil Engineers in 1892. The largest diagram
is a full-power diagram ; the diagram in dotted lines is half power ;
and the small light-line diagram shows the card given by the engine
when working without load. The various particulars of clearance
spaces, maximum pressure, pressure of compression, and stroke
volume are clearly shown upon the illustration. From these figures
it will be seen that the Priestman oil engine worked on a con-
sumption of -946 Ib. of Russoline oil per brake HP per hour, and
•842 Ib. of Daylight oil per brake HP per hour.
Professor Unwin states that the oil used in starting the engine
was insignificant in quantity, being only about one pound of oil
in each of the two trials in which it was measured.
The Samuehon Oil Engine.— Messrs. Samuelson's engine is
constructed under the Griffin patents, and it resembles Priestman's
in subjecting the oil to the preliminary process of spraying before
vaporising, and in it also the vaporiser is heated during the run-
ning of the engine by the exhaust gases. It differs, however, from
the Priestman engine in the methods of igniting and governing.
The tube igniter is used, and, instead of reducing the power of
the explosions as is done by Messrs. Priestman, the governing
device so operates that when speed becomes too high, the air
supply is entirely cut off, and the exhaust valve is also closed.
Oil Engines
417
The exhaust valve is closed after the combustion products of
the last explosion have been discharged from the cylinder, the
piston consequently moves out, expanding the contents of the
compression space.
The oil valve is simultaneously shut off in the sprayer, so that
no oil is injected.
Fig. 192 is a section of the Griffin patent oil sprayer. The
air enters by way of the passage A, and discharges through the
nozzle A', thereby creating a partial vacuum in the annular space
B formed between the air nozzle and the oil nozzle. The passage
I ft -
UftMT
AGRA*
*• STROKE VOiUMC
- -*- -39$i
FIG. 191. — Priestman Oil Engine (diagram, Unwin).
B2 connects to the oil-supply chamber B' by way of a spraying valve
c attached to a plunger stem c'. The air pressure, when admitted,
forces down the plunger c', and thus opens the valve c against the
pressure of the spring. Oil thus passes up the passage B2 from the
chamber B', and is discharged with the air from the nozzle A' in a
state of fine spray.
Whenever the air pressure is removed from the plunger c', the
spring forces the valve to its seat, and cuts off the oil supply.
The air pressure is maintained at from 12 to 15 Ibs. above
E E
4i8
Oil Engines
atmosphere by a pump driven from an eccentric on the valve
shaft.
The vaporiser is shown in longitudinal transverse section, plan
and end elevation at fig. 193. E is the vaporiser, made of cor-
rugated outline, and surrounded by the exhaust jacket F. The
air is admitted to the vaporiser from the atmosphere by the
adjustable perforated plate G, and the spray nozzle is attached
at a point H, and discharges the spray into the centre of the
vaporiser.
FIG. 192. — Samuelson (Griffin) Oil Sprayer.
So far the arrangements closely resemble those of the Priestman
engine ; but, instead of using the electric spark for igniting, the
incandescent tube is adopted, and an incandescent metal tube is
heated and kept hot by an ingenious lamp shown at fig. 194. In
this lamp oil is admitted to the chamber j by the pipe K, and it is
maintained at a constant level there by means of the overflow pipe L.
A short piece of wire M is immersed in the oil, and the oil runs up
the wire and covers the bent part by reason of capillary attraction.
Air under pressure is admitted by way of the pipe N adjusted by
Oil Engines
419
the screw N', and it passes to the nozzle o, striking upon the bent
part of the wire M. The air thus blows the oil off the wire, and
' FIG. 193. — Samuelson Engine Vaporiser.
at the same time the jet sucks in a further supply of air through
holes P, and the mixed air and oil spray pass through the tube Q
to the asbestos-lined funnel R ; on igniting the mixture within this
FlG. 194. — Samuelson Engine Spray Lamp.
funnel, it burns with a fierce blue flame, and heats up the igniter
tube s ; this tube opens into the engine cylinder, and ignites the
mixture when it is compressed. To start the engine, the air pump
E E 2
420 Oil Engines
is worked by hand until the required pressure is obtained ; air is
then turned on the sprayer, and the spray lighted. By this means
the vaporiser is heated for about ten minutes from within, the
burned gases being discharged through a special valve opening
into the exhaust, which valve is closed when sufficient heat is
attained, The heating lamp of the incandescent tube is in the
meantime lighted, and the engine is ready to start.
No independent tests have been made of the power and oil
consumption of this engine within the author's knowledge.
Engines in which the Oil is injected into the Cylinder and
vaporised within the Cylinder. — -The engines at present in use in
Britain falling under this head are those manufactured and sold
by Messrs. Hornsby of Grantham, Messrs. Robey of Lincoln, and
a German engine known as the * Capitaine.' Messrs. Hornsby
term their engine the Hornsby-Ackroyd engine, and it is un-
doubtedly the most successful and simple of this type.
Hornsby-Ackroyd Oil Engine. — Fig. 195 is a section through
the vaporiser and cylinder of the Hornsby-Ackroyd engine, and
fig. 196 shows the inlet and exhaust valves also in section placed
in front of the vaporiser and cylinder section. The main idea of
this engine is simple in the extreme. Vaporising is conducted
in the interior of the combustion chamber, which chamber is so
arranged that the heat of each explosion maintains it at a tem-
perature sufficiently high to enable the oil to be vaporised by
mere injection upon the hot surfaces, the heat being also sufficient
to cause the ignition of the mixture of vapour and air when com-
pression is completed. The vaporiser A is heated up by a
separate lamp, the oil is injected at the oil inlet B, and the engine is
rotated by hand. The piston then takes in a charge of air by the
air inlet valve into the cylinder, the air passing by the port directly
into the cylinder without passing through the vaporiser chamber.
While the piston is moving forward taking in the charge of air the
oil which has been thrown into the vaporiser is vaporising and
diffusing itself through the vaporising chamber, mixing, however,
only with the hot products of combustion left by the preceding
explosion. During the charging stroke the air enters through the
cylinder, and the vapour formed from the oil is almost entirely
confined to the combustion chamber. On the return stroke of
Oil Engines
421
the piston air is forced through the somewhat narrow neck a into
the combustion chamber, and it there mixes with the vapour con-
tained in it. At first, however, the mixture is too rich in inflammable
FIG. 195.— Hornsby-Ackroyd Engine
(section through vaporiser and cylinder).
vapour to be capable of ignition. As the compression proceeds,
however, more and more air is forced into the vaporiser chamber,
and just as the compression is completed the mixture attains
FIG. 196 — Hornsby-Ackroyd Engine
(section through valves, vaporiser, and cylinder).
proper explosive proportions. The sides of the chamber are
sufficiently hot to cause explosion, and the piston moves forward
under the pressure of the explosion so produced.
As the vaporiser A is not water -jacketed, and is connected to
422 *. Oil Engines
the metal of the back cover only by the small sectional area of cast
iron forming the metal neck a, the heat given to the surface by
each explosion is sufficient to raise, its temperature to about
700-800° C. and keep it there.
It is a peculiar fact that oil vapour mixed with air will explode
by contact with a metal surface at a comparatively low tempera-
ture, and this accounts for the explosion of the compressed
mixture in the combustion chamber A, which is never really raised
to a red heat. It has long been known to engineers conversant
with gas engines that under certain conditions of internal surfaces
a gas engine may be made to run and ignite with very great
regularity without incandescent tube or any other form of igniter,
FIG. 197. — Cylinder Ignitions, Otto Engine.
if some portion of the interior surfaces of the cylinder or combus-
tion space be so arranged that the temperature can rise moderately ;
then, although that temperature may be too low to ignite the
mixture at atmospheric pressure, yet when compression is com-
plete the mixture will often ignite in a perfectly regular manner.
Fig. 197 shows a series of diagrams taken from the ordinary Otto
engine igniting in this manner without any special igniter, and it
will be observed that the diagrams are very fairly regular. The
author has noticed this peculiar fact in connection with one of
his old engines described on page 184. He placed a stud A,
fig. 1 98, in the end of the piston B ; this stud was sufficiently long
to project the head well into the explosive mixture ; on starting
Oil Engines
423
the engine with the ordinary flame-igniting valve and running it
for 15 minutes in the usual way, it was found that the flame-
igniting arrangement could be entirely stopped from action and
the engine run regularly, the mixture igniting only because of the
incandescent head of the bolt A, which projected into the explosive
mixture after compression and ignited only when the mixture was
fully compressed. In this arrangement, however, the bolt A was
found to attain a high red heat.
It is a curious and interesting fact that with heavy oils ignition
is more easily accomplished at a low temperature than with light
oils. The explanation seems to be that in the case of light oils
the hydrocarbon vapours formed are tolerably stable from a
chemical point of view, but the heavy oils very easily decompose
by heat and separate out
their carbon, liberating the
combined hydrogen, and at
the moment of liberation
the hydrogen being in what
chemists know as the nas-
cent state very readily enters
into combination with the
oxygen beside it. In this
manner combustion is more
easily started with a heavy FlG- iQS.-Clerk Engine with bolt igniter,
oil than with a light one.
Messrs. Hornsby's vaporiser is of D shape, the rounded part
above and the straight part of the D below.
To start the engine the vaporiser is heated by a separate
heating lamp, which lamp is supplied with an air blast by means
of a hand-operated fan. This operation should take about nine
minutes. The engine is then moved round by hand, and starts in
the usual manner. The oil tank is placed in the bedplate of the
engine. The air and exhaust valves are driven by cams on a valve
shaft.
Figure 199 is a general view of the external appearance of the
engine, from which it will be seen that the governing is effected
by a centrifugal governor. This governor operates a bye pass
valve, which opens when the speed is too high and causes the oil
424
Oil Engines
pump to return the oil to the oil tank. The fan and starting lamp
will be seen in the lower part of the illustration.
Tests and Oil Consumption. — Messrs. Hornsby's engine was
exhibited at the Royal Agricultural Show at Cambridge, and after
an exhaustive test by the judges of the show in competition with
engines by nine other makers, the Hornsby engine was awarded
the first prize of 5o/. The engine tested was given as of 8 brake
HP, and its dimensions were — diameter of cylinder 10 in.,
stroke 15 in., weight of engine 40 cwt. During the trials,
according to Professor Capper's report, the engine ran without
FIG. 199. — Hornsby-Ackroyd Oil Engine.
hitch of any kind from start to finish. Its action was faultless.
One attendant only was employed all through the trials, and
started the engine easily and with certainty after working the hand
blast to the lamp for 8 minutes. During three days' run the
longest time taken to start was 9 minutes, and the shortest
7 minutes. When the engine stopped each day the bearings
were cool and the piston was moist and well lubricated ; the
revolutions were very constant, and the power developed did not
vary one quarter of a brake HP from day to day. The oil
consumed, reckoned on the average of the three days' run, was
•919 Ibs. per brake HP per hour. The oil used was Russoline,
Oil Engines 425
sold in Cambridge at that time at the price of $\d. per gallon.
At this rate the cost for oil per brake HP was £</., and this
included all the oil used for the starting lamp.
Mr. C. F. Wilson, F.C.S., has made an analysis of the
Russoline oil used for the purpose of testing the oil engines
exhibited at Cambridge, and found that the specific gravity at
60° F. -824, the flashing point (Abel test) 88° F., the total heat of
combustion was 11*055 calories, but after deducting for the heat
due to the condensation of water vapour this reduced to 10*313
calories. The oil contained 14*05 per cent, hydrogen. Mr.
Wilson makes the observation that this oil appears to be very
constant in composition, because a similar oil examined by him a
year before gave 14*07 per cent, hydrogen, and a corrected
calorific value of 10-3 calories, so that the two samples supplied
at an interval of a year were practically constant in com-
position.
The mean power exerted during the three days' trials was
8 -3 5 brake horse. At a subsequent full-power trial of the same
engine at the show, a brake HP of 8*57 was obtained, the
engine running at a mean speed of 239*66 revolutions per
minute and the test lasting for two hours ; the indicated power
was 10 -3 horse, the explosions per minute 1 19*83, the mean
effective pressure 28*9 pounds per square in., the oil used per
IHP per hour was *8i and per brake HP per hour -977 pounds.
According to Professor Capper the heat account of the engine
was :
Heat shown on indicator diagram IHP . . i6'9 per cent.
Heat rejected in jackets . . . . . .29*5 ,,
Heat rejected in exhaust and other losses . . 53 '6 ,,
In these tests, however, Professor Capper erroneously takes
the corrected heat value of the oil instead of the total heat value.
In determining the absolute efficiency of any engine, it is neces-
sary to take as a basis the total amount of heat evolved by the
combustion from the atmospheric temperature to the atmospheric
temperature again. The author has recalculated these figures, and
finds the correct heat account below :
426 Oil Engines
Heat shown on indicator diagrams per IHP
Heat rejected in jackets . , . .
Heat rejected in exhaust and other losses
15-3 per cent.
26-8
57'9
In a test of this engine made at the same time but
half-power, the brake HP developed was 4-57 at 235-9 revolu-
tions per minute, and the oil used per brake HP per hour was
1-49 pounds. On a four hours' test with this engine running
entirely without load at 240 revolutions per minute it was found
that it consumed 4-23 pounds of oil per hour. Fig. 200 is a card
Ibs. per sq.
absolute
1+0
110
/CO
so
60
40
20
o
in.
py
\
\
s^
*s
N
"V.
^
^"^
•^
^^
^^
^ —
•^•^
^*^
^
•9 /-O /•/ cb. ft..
Brake HP, 8*57; indicated HP, 10*3; diam. of cylinder, 10" ; stroke, 15"; revs,
per min. 239*66 ; explosions per min. 119*83 ; mean pressure, 28*9 Ibs. per sq. in. ;
pressure ot explosion, 112 ibs. per sq. in. above atmos. ; pressure of compression,
50 Ibs. ; oil per IHP hour, *8t Ibs. ; oil per BHP hour, '977 Ibs.
FIG. 200 — Hornsby-Ackroyd Oil Engine (diagram).
Average card, two hours' full power trial. Russoline oil.
from the Hornsby engine, being an average card of the two hours'"
full-power trial. The cylinder volume is given in cb. ft. and the
compression space is also given. From this diagram it will be
observed that the average pressure, the maximum pressure and
the pressure of compression are very low, and that consequently a
large cylinder is required to develop a given power, while it is
worth observing how beautifully regular is the ignition obtained by
the simple device of firing from the surfaces of the hot combustion?,
chamber.
Robey Oil Engine. — The Robey oil engine is constructed in*
Oil Engines
427
accordance with the patents of Messrs. Richardson and Norris
and it very closely resembles the Hornsby-Ackroyd engine.
Like the Hornsby engine, it depends upon the heat of the
combustion space walls both for vaporising and igniting, and
the governing is effected by diminishing the oil supply. It
differs, however, from the Hornsby engine in this, that the com-
bustion chamber is made with a water jacket, and an inner
lining is inserted from behind, which lining stands clear of the
water-jacketed part and becomes hot by the explosion. Fig. 201
is a section showing one arrangement of the combustion chamber
of the Robey engine. The
liner A is introduced into
the combustion chamber
from behind, and it is easily
removed when it is desired
to clean or repair. The
engine also differs, it will be
observed, in the position of
the inlet and exhaust valves.
The charge, instead of pass-
ing directly into the cylinder
as in the Hornsby engine,
passes first outside the com-
bustion space into the cylin-
der. The author is unaware
of any official test of this
engine, but fig. 202 is a diagram taken by him from a Robey oil
engine of 6 in. cylinder and 9 in. stroke running at 260 revolu-
tions per minute, and using American oil having a specific gravity
of '857 at 50° F. The diagrams from Messrs. Hornsby's and
Robey's engines prove that this system of ignition and vaporising
supplies a very regular and effective ignition.
Capitaine Oil Engine. — The Capitaine oil engine resembles
the Robey engine in surrounding the combustion chamber with a
water jacket, and in introducing an internal liner kept clear of the
water-jacketed sides to give sufficient heat for the purpose of vapo-
rising and igniting. An engine of this type was entered for trial at
the Royal Agricultural Show at Plymouth, and it was declared at
FIG. 201.— Robey Oil Engine
(section through combustion space).
428
Oil Engines
5 brake HP, cylinder 7^ in. diameter, stroke 7^ in., speed 300
revolutions per minute, weight 17 cwts. The engine was designed
to use Tea Rose oil, and the adjustments were found to be un-
suitable for the use of Russoline oil, which was the oil settled by
the judges for use during competition. The engine was therefore
withdrawn from the competition, and the author is unaware of
any official tests. In his report, however, Professor Capper says
that using Tea Rose oil the engine runs at 300 revolutions per
minute and develops \\ brake HP, starting from the moment
of heating the vaporiser in about five to ten minutes. Fig. 203
is a section through the vaporiser and combustion chamber. A
is the inlet valve operating automatically. It contains a central
tin pt,r Sa in
absolute,
/20m
/OO
80
60 V
40 -
£0 -
O L
FlG. 202.— Robey Oil Engine (diagram, Clerk).
spindle B, having at the point of it a valve seat b. The valve A
has thus two seats, one the usual external seat and the other an
internal seat, closing 'on its valve seat b. The spindle B operates
within a hollow, having a hole c opposing the oil supply pipe D.
E is the vaporiser, which is surrounded by a non-conducting
casing F, which in turn is inclosed in a metal casing G within the
combustion space H. i is the water jacket.
To start the engine the vaporiser is heated by a hand spirit
lamp. This operation takes from five to ten minutes, and according
to Professor Capper the engine then starts away very easily. On the
suction stroke the air inlet valve opens, thereby opening also the
Oil Engines
429
internal valve, and air passes into the cylinder, mostly passing round
outside the casing. A portion, however, passes through the centre of
the valve, and with it enters the oil from the pipe D. A small quantity
of oil and air thus passes through the centre of the vaporiser E,
and the vapour enters the cylinder to form mixture for explosion.
Upon compression the compressed mixture ignites at the internal
hot surfaces of the vaporiser E.
The vaporiser E, with its non-conducting material F and
outer casing G, is all immersed in the flame of the explosion ; but
the vaporiser E becomes hottest because it is not subject to the
cooling action of the air supply, which mostly passes round be-
tween the casing F and the
combustion chamber. Only
a small portion of air passes
through the hole c with the
oil entering the pipe D ; the
surface G also radiates more
heat to the cold walls, so that
the vaporiser is kept at the
highest temperature by the
repeated explosions.
The oil pump used in the
Capitaine engine is of peculiar
construction. Fig. 204 is a
section. The plunger A is
operated by bell crank lever,
roller and cam, actuated in
the usual way ; and a slide
valve B is actuated also by
lever c and cam D ; the plunger is packed by leather packing,
and operates in a glycerine bath F. Oil G floats on the top of
the glycerine bath, and is discharged through the slide valve B.
In this way the plunger A is caused to operate in a space of ample
capacity.
Engines in which the Oil is vaporised in a Device external to the
Cylinder ; and introduced into the Cylinder in the state of Vapour. —
Engines falling under this class are manufactured by Messrs.
Crossley, Tangyes, Fielding & Platt, Campbell Gas Engine Co.,
FIG. 203. — Capitaine Oil Engine
(section through vaporiser).
430
Oil Engines
Ltd., the Britannia Co., Clarke, Chapman & Co., Weyman &
Hitchcock, and Wells Bros.
Cross ley Brothers' Oil Engine. — Fig. 205 shows the general
appearance of Messrs. Crossley's oil engine. In this engine a
separate vaporiser is arranged, communicating with the cylinder
by a vapour valve. The engine is ignited by an incandescent
tube, and both incandescent tube and vaporiser are heated by
the same lamp. The exhaust and air-inlet valves are placed in
opposition to each other, the air-inlet valve being automatic and
above the exhaust valve ; both open into the cylinder combustion
space. The exhaust valve
& G is Actuated in the ordinary
manner from the valve
shaft. The governor is an
ordinary rotating governor
of the hit-and-miss type,
or in the small engines
an inertia governor, and
when the speed is exces-
sive a link is intercepted
which ordinarily opens the
vapour valve, and the valve
remains clos'ed. No charge
is then admitted to the
cylinder. The vapour valve
upon opening allows the
suction of the piston to
draw in a charge of oil to
the vaporiser, and oil, vapour and air from the vaporiser to the
cylinder. The charge admitted to the vaporiser is thus heated
during the period of an entire forward stroke. The air-inlet valve
is opened by the vacuum caused by the piston, and part of the
air, on its way to the cylinder, passes first through a heated coil,
and then through the vaporiser. The heated air charge thus
carries off the oil vapour through the vapour valve.
Messrs. Crossley have used several lamps for the purpose of
heating, but the type of lamp now used by them, and indeed by
many others, is that best explained by a description of a small
FIG. 204. — Capitaine Oil Engine
(section through oil pump).
Oil Engines
431
lamp sold as the Etna lamp. This lamp is shown in section and
plan at fig. 206, and its action and construction are as follows :
The lamp comprises a stout brass oil- and air-containing vessel
A, having fitted in it a small air pump B. This pump projects
within the vessel A, and has at its lower end a pump valve opening
inwards, which allows the air to pass from the pump into the
vessel, but prevents it leaking back into the pump. The pump
leathers cup downwards, to close tight when the air is compressed ;
but when the piston is withdrawn the air passes the leathers on
FIG. 205.— Crossley Oil Engine.
the up-stroke, so that no second valve is required. The piston
leathers act as a valve in the manner so well known in connection
with pneumatic tyre inflating pumps. The vessel A has also an
oil filter c, an air-relief pin D, and above it carries the lamp proper,
consisting of a continuous arrangement of tubes and passages,
E, F, G, H, which communicate with the oil in the vessel A by the
pipe E, which dips to nearly the bottom of the vessel. The tube
E leads from the oil vessel to the square coil F, seen more clearly
in dotted lines on the plan. The tube G leads from F into a pas-
sage shown in the casting H. The casting is drilled out to carry a
432
Oil Engines
fine nozzle piece i, fitted on as shown. A hood or sleeve j is
slipped over the whole tube arrangement. The sleeve has two large
FIG. 206.— Etna Lamp.
air inlet holes K, one of which is clearly seen in the section. Smaller
holes are made in the sleeve opposite the square tube piece F.
Oil Engines 43 3
To start the lamp, the vessel A is partly filled with petroleum
by way of the oil cup c, the cap is screwed on, and the saucer-
shaped depression in the top of the vessel A is filled with spirit
and ignited. The flame produced heats up the tube arrangement
and the funnel or hood. About one minute suffices to heat it to
a high enough temperature for starting. The air pump B is now
operated, and air is forced into the vessel A under pressure, and
it presses upon the surface of the oil and forces it up the tube E.
It rises in the tube till it reaches the hot part, when the oil is
caused to boil and vapour is generated ; this vapour issues at the
small jet i, and as this jet is small the pressure rises. The vapour
jet ignites at the external flame, and a powerful flame shoots into
the hood j, and by its motion sucks in a charge of air by way
of the slots. The flame leaving the hood j is thus mixed
with air, and a powerful blue smokeless flame leaves the hood,
which flame is capable of heating up metal surfaces to incan-
descence without depositing soot. The flame plays on the tubes
E, F, G, and so supplies heat to the oil. A small pressure of air is
required, and if excess has been pumped in, it is discharged by
the plug D.
If too great an air pressure be given, the air will force the oil
up to the jet i, but with the correct pressure the air just keeps the
oil high enough in the tube E to generate sufficient vapour. Pegs
are arranged to allow the tubes to be cleaned. A few strokes of
the air pump, supply air sufficient to operate the lamp for
hours.
Fig. 207 shows a vertical section and a sectional plan of the
Crossley vaporiser and incandescent tube. The sectional plan is
taken on the line x Y of the vertical section, through the vapour
admission and igniting port of the engine, and the sectioned metal
zs part of the back cover or end of the combustion chamber. The
combustion chamber is thoroughly water-jacketed like the rest of
the engine. When the suction stroke of the engine begins, the
vapour valve G is opened by the bell crank lever, operated from
the valve shaft by a link. This link is controlled by the
governor so as to either hit or miss the cam by a knife-edge
contrivance. While the engine is at work, therefore, the valve G is
either entirely opened or entirely closed on the charging stroke,
F F
434 Oil Engines
and the governing is the same as the usual gas engine governing.
When the valve G is opened considerable suction to the engine
cylinder is caused, as the air inlet valve to the cylinder is
automatic, and is held to its seat by a spring. The vaporiser
passages communicate with the vapour valve G, and a small
quantity of heated air passes over the oil and carries off the
vapour. The vaporiser is heated by the lamp, and the products
FIG. 207.— Crossley Vaporiser.
of combustion are discharged by the funnel D. Fig. 207 shows
this very clearly. The lamp produces a powerful Bunsen flame,
which first heats up the igniter c to incandescence, then it plays
on the vaporiser having drilled holes B B B B, and the gases pass
up the funnel. A casing surrounds the heated parts.
The funnel has an air space E surrounding it, which is divided
up by louvre projections. Small holes F open to the air at the
top. When the vapour valve G is opened, air is drawn in by the
Oil Engines
435
holes F, passes down the air space E, guided from side to side by
the baffle or louvre projections ; the air current reaches the passage
B and passes into the vaporiser, above the oil pipe or channel
A. The air there meets the liquid oil, also sucked in by the
partial vacuum, and the hot air carries the oil through the
vaporiser along the passage B, down along a similar passage
under it, and along B to the vapour valve G. The oil is thus
thoroughly vaporised and carried away by the hot air current.
One important point to insure effective vaporisation is to heat
the air thoroughly, and reduce its quantity as much as possible.
This is done by limiting the dimensions of the openings F. The
air and oil vapour pass by the valve G and admission port to the
FIG. 208.— Crossley Oil Measurer.
engine cylinder, and there mix with the air entering by the
automatic air inlet valve at the top of the cylinder ; the mixture is
then compressed and ignited when compression is completed by a
timing valve of the ordinary Crossley type connected to the
igniting tube c. The igniting tube c communicates with the ad-
mission passage by a small hole on the under side passing through
the casting of the vaporiser. The tube c is surrounded by a cast-
iron protecting tube to prevent too rapid oxidation.
The incandescent tube c has at its outer end an inlet suction
valve, which opens inward at each suction stroke, and thoroughly
clears out the burned gases of the last explosion, and so insures
certain explosion when the compressed mixture is admitted.
The oil supplying and measuring arrangements are very perfect.
F F 2
436 Oil -Engines
The pump does not measure the oil, but only supplies it in ex-
cess to a very simple measuring device. Fig. 208 is a diagrammatic
section of that device. The hole a is the oil-measuring aperture,
and it opens to the small lift valve b, which communicates with
the pipe A, fig. 207 ; oil is spirted from the end of the pipe c by
the pump, and it fills the hole a up to the top ; the excess oil
drains away to the chamber d and returns by the pipe e to the
reservoir in the tank in the base of the engine. When the
opening of the vapour valve causes suction in the vaporiser, the
valve b lifts, and the oil charge contained in the hole a is sucked
in, air following it to clear it all out into the vaporiser. By this
device a constant volume of oil is measured into the vaporiser for
each working stroke of the engine, and this measurement is
accurate and unvarying, even when the speed of the engine
changes.
The oil pump is large enough to discharge a considerable
excess of oil, and one pump plunger serves both for vaporiser and
lamp. The pump discharges through two lift valves, one of
which is loaded by a spring to lift at about 20 Ibs. per sq. in., and
the other is not loaded but lifts freely. The loaded valve dis-
charges to the vaporiser oil measurer, and the free valve discharges
to the lamp.
The lamp operates on the principle of the Etna lamp, but
instead of a coil, a gun-metal chamber is used, having a central
aperture for flame, a jet of small diameter at the foot of the
central aperture, and a pipe leading to the connected space from
the oil pump. The jet is very fine, and as the oil finds its way into
the chamber, vapour is formed which issues from the jet and
forms with air a Bunsen flame which heats up the lamp chamber,
and heats to incandescence the igniting tube as well as the
vaporiser and air heater. The lamp is started in the usual
manner by heating with flame from some oil-soaked rag or waste ;
this is done to avoid the use of any light oils for starting.
It is found by experience that the vapour jet hole should be
small enough to generate a pressure of not less than 20 Ibs. per
sq. in., and by the simple device of two discharge valves, one
loaded and one free, the vaporiser is fed with oil at 20 Ibs. pres-
sure. The vapour generated is thus kept at 20 Ibs. as the vapour jet
Oil Engines 437
produces sufficient resistance. If the pump sends too much oil,
then the liquid level in the vaporiser rises, and the increase in
vapour pressure holds the lift valve down and allows more oil to
discharge by the loaded valve. The lamp thus just gets oil
enough to generate vapour at 20 Ibs. By keeping the lamp
chamber under considerable pressure it is found that the small jet
hole does not choke up ; if the pressure be lowered, however, the
hole rapidly chokes up with carbon. This is obviously due to
the fact that by boiling under high pressure the oil decomposes
into lighter oils which do not readily carbonise, as explained in the
previous chapter. In stopping the lamp it should be stopped
suddenly by dropping the pressure rapidly ; by doing this the
hole escapes being choked up. Every morning before starting the
vapour hole should be pricked out with a very fine needle.
The vaporiser should be cleaned out every week ; this is
accomplished by taking off the scraped cover, which is held on by a
bolt, and putting in a steel rimer in succession to the four bored-
out holes of the vaporiser. By turning round the rimer the
carbon or coke which has formed in a week's run is easily cleared
out.
Tests and Oil Consumption. — A Crossley engine, declared of
7^ brake HP, was tested at the Cambridge Royal Agricultural
Show. Its dimensions were : Cylinder 7 ins. diameter ; stroke
15 ins. ; weight 32^ cwts. ; the speed per minute 210 revolutions.
During the test the engine ran admirably, and required very little
attention ; the average time taken to start was 16 minutes, the
maximum time taken being 19 minutes, and the minimum 13.
One attendant only was required. . As the result of the three
days' test, the engine developed on an average 6-28 brake HP, and
consumed -90 Ib. of Russoline oil per brake HP per hour. At a
full-power trial, lasting for two hours, the engine developed 7-01
brake HP, and indicated 7-9, running at a mean speed of 200-9
revolutions per minute. The oil used was 73 Ib. per I HP per
hour, and '82 Ib. per brake HP per hour. On a half-power
trial the engine developed 372 brake HP on a consumption of
1-33 Ib. of Russoline per brake HP per hour, the speed being
198-4 revolutions per minute. Running entirely without load
at 190 revolutions per minute, the engine consumed 2-53 Ibs. of
438
Oil Engines
oil per hour. Fig. 209 is an indicator diagram taken from this
engine, from which it will be seen that the maximum pressure of
explosion was nearly 240 Ibs. absolute, and the pressure of com-
pression about 80 Ibs. absolute. The mean available pressure
during the two hours' run was 72*2 Ibs. per square inch, the mean
number of cylinder explosions per minute being 7 5 '3. The oil
consumed by the Crossley engine is remarkably low, "82 Ib. of
lb per Sa. iin.
dbs. ^
FIG. 209. — Crossley Oil Engine (diagram).
Average card, two hours' full power trial. Russoline oil.
Russoline oil per brake HP per hour representing an expenditure
for fuel of -37^. Another trial of the Crossley engine was made
at the Show with Broxbourne oil. The power indicated was
8 -4, the brake power 7*63, the engine running at a mean speed
of 199*84 revolutions per minute. The mean effective pressure
was 63*6 Ibs. per square inch, and the oil per I HP per hour,
•72 lb. ; and per brake HP per hour, 785 lb. Although the
Oil Engines 439
engine runs with less of this oil per HP, yet it is to be remem-
bered that the oil costs $>\d. per gallon, and is not so economical
from a monetary point of view as Russoline oil.
Tangye Oil Engine. — This engine is made under Pinkney's
patents, and it resembles Crossley's oil engine in this, that the oil
is vaporised in a separate vaporiser, but the air charge is wholly
passed through the vaporiser to carry the vapour into the cylinder,
and the air so used is not subjected to any preliminary heating.
The ignition is effected by incandescent tube. The construction
and operation are as follows :
Fig. 210 shows a vertical section and plan of the oil attach-
ment to a Tangye gas engine. The vaporiser is a bottle-shaped
vessel A always in direct communication with the combustion
space of the engine by the passage B. c is the inlet valve to the
engine ; it is automatic, and is held to its seat by a spring. D is the
air inlet passage. E is the oil supply aperture which terminates
in a small hole F opening on the seat of the valve c and conse-
quently opened and closed by it. G is a coil lamp of the Etna
type, i is the igniting tube opening to the vaporiser. H is a bracket
for supporting the lamp G in its successive positions under the
vaporiser and under the igniting tube, j is a casing surrounding
the igniting tube, and K a casing surrounding the vaporiser. The
lever L (plan) operates a slide, which causes the hot gases from the
lamp, to pass either round the vaporiser or by the tube funnel j.
To start the engine the lamp G is first lit in the manner of the Etna
lamp and the vaporiser A is sufficiently heated. The lamp is
then shifted out on the bracket H, and the tube i is raised to
incandescence. The engine is then ready to start by turning
the fly-wheel. When in operation, on the suction stroke air
enters by the valve c, and at the same time oil discharges by the
aperture F, mixes with the entering air, and falls on the vaporiser
when it is vaporised, and passes into the cylinder with the air.
On the compression stroke the inflammable mixture is com-
pressed and ignites at the igniting tube i, producing a working
explosion. When the valve c closes, the oil supply is also
closed.
When governing, the governor holds open the exhaust valve
so that the exhaust gases are alternately drawn into and discharged
440
Oil Engines
from the cylinder ; during this action the valve c is held shut by
its spring, and no oil or air enters the cylinder. When the exhaust
FIG. 210.— Tangye Oil Engine.
Oil Engines
441
valve closes again, the oil and air enter the vaporiser and the
explosions begin again.
The oil is fed by gravity from an oil reservoir mounted above
the engine by a pipe to the passage E ; adjusting devices are
applied at the reservoir end.
The engine is a very simple one, but in the author's opinion
442
Oil Engines
all systems of feeding oil by gravity are bad, and with large
engines such systems are likely to be dangerous.
The author is unaware of any independent tests of this
engine,
Fielding 6° Platfs Oil Engine, — Fig. 211 is a general view
of Messrs. Fielding & Platt's oil engine. Fig. 212 is a section
through the vaporiser, and the admission port to the engine
cylinder. In this engine the vaporiser and igniter tube are
combined. A is the vaporiser, B the combined vaporiser and
igniter tube, c is an air heating tube, and D is a valve com-
municating between the vaporiser and the igniter tube. The
FIG. 212. — Fielding & Platt's Oil Engine (section through vaporiser).
whole system, A, B, and c, is inclosed within a casing E and heated
up by means of a lamp F. This lamp is of substantially the same
construction as the Etna, described at page 431 of this work. That
lamp has an air reservoir G and an air pump H, and the lamp part
F is arranged to produce a vapour jet which sucks in by induction
sufficient air to form a strong blue Bunsen flame. In this engine
the exhaust and air inlet valves are situated opposite each other,
opening into the same port. In oil engines this is a highly
desirable arrangement, because it is advisable to heat the main
air supply to some extent as it enters the engine, and this is better
done by causing the air to impinge upon the hot exhaust valve
and pass through the hot exhaust port before reaching the engine
Oil Engines 443
cylinder. To start the engine the lamp is ignited and the igniter
tube, vaporiser tube, and air tube are heated up. Oil is then
injected by means of a small suction pump and discharged by
the jet a into the vaporiser A ; on the suction stroke of the engine
the air valve i opens, and air is drawn into the engine cylinder.
At the same time air passes by means of a small air inlet
aperture K through the air heating tube c to the chamber b, and
thence to the vaporiser tube A. The valve D is opened by a cam
during the suction stroke, and the air and vapour pass together
through the igniter tube B into the cylinder. The charge of oil
is thus sucked through at each stroke and taken into the engine
cylinder by a small quantity of air, there to mix with a larger
quantity of air already in the cylinder. The port L is somewhat
large, and it becomes hot by the exhaust gases and by the
explosion, and so maintains the vapour without condensation as
it enters the cylinder.
An engine was exhibited by Messrs. Fielding & Platt at the
Cambridge Show. Its dimensions were — diameter of cylinder
8J ins., stroke 16 ins., weight of engine 53 cwts., declared speed
170 revolutions per minute. In this engine all the valves, air
valve, vapour valve, and exhaust valve are actuated from one cam,
and the governor of the usual hit-and-miss type cuts out explo-
sions when the engine exceeds its speed by holding open the
exhaust valve and keeping the air and vapour valves closed. The
piston thus runs to and fro, taking the exhaust gases into the
cylinder from the exhaust pipe, and returning them to it again.
During the trial at the show the lamp is stated to have given too
little heat, and consequently rendered the ignitions late. The
engine ran very steadily, however, and started very readily with
one attendant only, twenty-two minutes being consumed ' in
heating up. As the late ignition could not be remedied at once
the engine was withdrawn from the test.
Tests and Oil Consumption. — Messrs. Fielding & Platt have
been good enough to send the author particulars of the results ob-
tained with the engine (see table, p. 444), together with a diagram
from which fig. 213 has been prepared. The tests and diagram
show the engine now to be in thoroughly good order.
The results are very good indeed ; a consumption of o'8o lb*
444
Oil Engines
of Russoline oil per brake HP hour is superior to that given by
the first prize engine at the Cambridge Show.
TESTS OF A 3 HP NOMINAL FIELDING & PLATT OIL ENGINE
MADE BY MESSRS. FIELDING & PLATT ON NOVEMBER 22 AND 23, 1894.
Power
Full
Half
Light
Full
Duration of test
i hour
i hour
i hour
3 hours
Revolutions per minute
220
225
230
222
Explosions per minute
100
84
18
100
Nett brake load
63 Ibs.
33 lbs-
—
63 lbs.
Diameter brake circle
4ft-
4 ft.
4 ft.
4 ft.
Brake HP
5-28
2-8
—
5 '3
Oil per hour in Ibs. (Russoline)
475
3 '5
i "3
4-24
Oil per brake HP hour .
©•90 Ib.
I-25lb.
0-80 Ib.
Available pressure average of
four diagrams, 79 Ibs.
Fig. 213 is a diagram from a similar 3 HP nominal engine
taken in a test made on October 22, 1895, which also shows the
excellent result of '8 Ib. of oil per brake HP hour. During that
test the engine gave 5-5 HP on the brake at 219 revolutions per
minute, the compression was 40 Ibs. and the maximum pressure of
the explosion was 140 Ibs., while the available pressure was 63 Ibs.
FIG. 213. — Fielding & Platt's Oil Engine (diagram).
Messrs. Fielding & Platt state that ten minutes suffice for the
heating of the igniter and vaporiser, and that having started the
lamp it is only necessary for the driver to go round the engine
and examine and fill up lubricators ; after this the vaporiser will
be hot enough, and on giving the fly-wheel a turn or two the
engine starts. A half compression cam is provided to ease the
starting.
Oil Engines
445
This engine is extremely simple, and the timing valve is
entirely dispensed with, the igniter tube B being at all times open
to the cylinder. The engine is exceedingly economical at light
loads as well as at full load.
FIG. 214.— Campbell Oil Engine (section through vaporiser and igniter).
Campbell Oil Engine.— The. Campbell engine resembles the
Tangye engine in its vaporising arrangements. There are only
two valves, inlet and exhaust ; the air inlet is automatic and the
exhaust is operated in the usual manner. In this engine also there
are no oil pumps ; the vaporiser is fed by gravity, and so is the
446
Oil Engines
lamp. Ignition is produced by incandescent tube, and the
vaporiser and tube are heated by a lamp. The engine resembles
the Tangye in passing the whole of the air charge through the
vaporiser to carry off the vapour when formed. Fig. 214 is a
section through the vaporiser and igniter tube of the Camp-
bell oil engine. Fig. 215 is a horizontal section showing the
exhaust valve and the end of the vaporiser. Fig. 216 is a side
FIG. 215. — Campbell Oil Engine (horizontal section through exhaust valve).
elevation of the end of the engine, showing the operation of the
governor.
An automatic inlet valve A serves for admission of the whole
air charge to the cylinder by way of the vaporiser B and passage
G. The oil is fed by gravity and passes through the supply pipe
c to an annular channel D round the seat of the valve A, and is
injected through perforations E to mix with the air when the valve
Oil Engines
447
opens. This valve, like the Tangye, resembles the gas and air
valve first introduced by Clerk. On the suction stroke of the
engine, air enters by the valve A, and oil entering with it is carried
through the vaporiser, and the mixture of inflammable vapour and
air passes into the engine cylinder by the passage G ; this passage
G leads into the exhaust port, as clearly seen at fig. 215, and thus
one port serves for the admission of the charge to the cylinder and
the discharge of the exhaust products. The igniter tube H is
FIG. 216. — Campbell Oil Engine (side elevation of cylinder end).
screwed into the bend of the vaporiser and is always in open com-
munication with it. The lamp which heats the tube also heats the
vaporiser, but while at work the heat of the explosions is sufficient
to keep up the vaporiser temperature. The explosion ensues
upon compression, the inflammable mixture being forced into the
hot tube. This engine, however, is found to ignite without the
tube after running for some time.
The governing is accomplished by a ball governor i, fig. 216,
which controls the exhaust valve j. This valve is opened at every
448
Oil Engines
exhaust stroke by the sliding piece K, which at one end of its stroke
strikes the pin L, and by moving the lever M opens the exhaust
valve. When the engine speed rises above normal the governor
sleeve rises and moves the lever N and link o ; this interposes the
small plate P between the outer end of the lever M and the stationary
bracket Q. The exhaust valve spring is thus prevented from
pulling the valve back to its seat until the speed falls again. The
FIG. 217.— Campbell Oil Engine (diagram).
holding open of the exhaust valve j thus prevents the suction
of a charge of oil and air through the automatic valve A. This
engine, like the Tangye, is very simple, but in the author's opinion
the oil fed by gravity is troublesome, and in all but small engines
is also likely to be dangerous.
Tests and Oil Consumption. — A Campbell engine was tested
at the Cambridge Royal Agricultural Show. The engine was de-
clared as of 6 HP nominal, the diameter of the cylinder was 7^ ins.,
Oil Engines
449
and the stroke 12 ins. The declared revolutions were 240 per
minute. The engine weighed 27 cwts. In a three days' test it
gave 475 brake HP on an oil consumption of 1*15 Ib. Russoline
oil per brake HP. - In a subsequent full power test the engine gave
4-8 1 brake HP, and indicated 5-9 horse on a consumption of -93
Ib. of oil per I HP per hour, and 1*12 per brake HP per hour.
The average speed during the trial was 2077 revolutions per
minute, and the average pressure developed in the cylinder was
65*5 Ibs. Fig. 217 is a dia-
gram taken from the Camp-
bell engine during a two hours'
test. The Campbell ran with-
out load at 211 revolutions per
minute on a consumption of
2 '32 Ibs. of oil per hour.
Britannia Oil Engine. —
The Britannia engine is the
invention of Mr. Roots, and in
it also the air heater, vaporiser,
and incandescent tube are
neatly combined in one cast-
ing. The oil feed arrangement
too is ingenious, and dis-
penses with a pump of the
ordinary type. Fig. 218 is a
section showing the air heater,
vaporiser, and ignition tubes,
as also the air inlet valve of
the engine. Fig. 219 is an
end elevation part in section
showing the action of the oil
feed. Oil is fed to the oil bath A, fig. 219, and is kept at a con-
stant level in that bath by the overflow hole a. A spindle B is
reciprocated to and fro by the levers c, D, and a cam E on the
valve shaft F. The governor lifts the lever G, carrying the trip
piece H, shown in dotted lines, and so long as this trip piece is
held opposite the operating edge of the lever D, the spindle is
moved. When the governor lifts the trip piece the spindle B
G G
FIG. 218 Britannia Oil Engine
(section through vaporiser).
450
Oil Engines
remains stationary. Grooves b are cut round the spindle B ;
these grooves fill with oil, and on pulling the spindle B through
\Q the chamber i the oil falls off or is blown off by the passing air.
This chamber is seen at i in fig. 218 as well as in the end elevation.
The upper part of that figure shows a spiral cr louvre deflecting
plate device, forming part of the casing K ; air enters at the upper
part, passes over the deflecting plates which are heated by the
flame, serving to heat the ignition tube L. The ignition tube L is
placed in a circular casing, the upper part of which carries the
FIG. 219. — Britannia Oil Engine (oil feed and governing).
deflecting plates referred to, and the lower part carries the
vaporiser M. The air enters the engine by way of the deflecting
plates, passes over them, and becomes heated, then strikes upon
the oil supply spindle B and removes the oil from the grooves,
carrying it into the vaporiser, and then carrying the oil from the
vaporiser M to the air inlet valve N, and thence by the inlet port o
to the engine cylinder. Ignition is caused at the proper time by
the compression of the combustible mixture into the hot ignition
tube L.
Oil Engines
451
The lamp used in the Roots engine is shown at fig. 220, which
is an elevation part in section. It is of the now standard type
like the Etna, and consists of a tube A bent round upon itself to
form an elongated loop. At the end B of the loop is arranged a
small opening c, in which a conical pin D fits. The point of the
pin projects through the small hole E, and so forms an adjustable
annular orifice. An oil vessel F is connected to the tube A, and
FIG. 220. — Britannia Oil Engine (lamp).
has attached to it a small air pump G. Outside the bent pipe A
is a sleeve or hood H open at both ends.
To start the lamp the tube A and hood H are first heated by
a piece of waste soaked in oil and lighted. Air is pumped into
the reservoir F by means of the small air pump G until the oil is
forced through the asbestos I contained in the tube ; the oil heats
and boils off, discharging as a strong jet at the annular orifice
G G 2
452
Oil Engines
made by the pin D. The jet is lit and the flame heats the bent
tube and is discharged out of the hood H as a fierce blue smoke-
less flame.
This lamp is similar to the others, but the small points of detail
peculiar to it are interesting.
The Britannia engine, like the Tangye and Campbell, takes in
the whole air charge through the vaporiser.
Tests and Oil Consumption. — One of the Britannia engines was
Ibper Sain
200
ISO
160
MO
/ zo
too
so
60
40
20
\
•/ "2 '3 ^ 'S
FIG. 221. —Britannia Oil Engine (diagram).
tested at the Cambridge Show ; its dimensions were — diameter of
cylinder 7^ ins., stroke 13 ins., declared revolutions per minute 235,
weight of engine 33 cwts., declared power 7 brake horse. On a
three days' test the engine developed on an average 6-15 brake
horse and consumed 1-49 lb. of oil (Russoline) per brake
horse hour. On the subsequent full power test, lasting for two
hours, the engine gave 6-21 brake HP and indicated 8-4 HP.
Running at 240 revolutions per minute and giving a mean effec-
tive pressure of 47*3 Ibs. per sq. in., the oil consumed was
Oil Engines 453
1-25 Ib. IHP hour, and r68 Ib. per brake HP hour. On half
power the engine developed 3-96 brake horse, consuming 1-67 Ib.
per brake horse hour. Running light without load the engine
made 256 revolutions per minute, and consumed 1*44 Ib. of
Russoline oil per hour. It is a somewhat remarkable fact that
this engine, which consumed the largest amount of oil per HP
of any of the engines tested at the Cambridge Show, ran with
no load at full speed on the lowest consumption of oil of any.
Fig. 221 is a diagram from this engine taken during the two
hours' trial. In the trials this engine was found to require 12 and
13 minutes to start ; on one occasion however it took 24 \ minutes
to heat up for starting.
Clarke ', Chapman 6° Co.'s Oil Engine. — A vertical longi-
tudinal section of this engine is shown at fig. 222, and a
transverse section at fig. 223. The engine is peculiar among
petroleum engines in dispensing entirely with lift valves and
depending for all the operations of the engine upon a rotating
plug valve. This valve is rotated by a shaft driven at one fourth
of the speed of the crank shaft, and by its rotation the whole of
the operations of admission and exhaust are performed ; the
ignition is obtained by means of the electric spark. Although the
vaporising and valve actions of this engine present externally a
simple appearance, yet internally they are extremely complex, too
complex in the author's opinion to be suitable for the rough con-
ditions of public use. A is the plug valve rotated as described by
the valve shaft B. The port A1 through the valve is the exhaust
port which connects by means of another port A2 with the exhaust
pipe. A3 is one of the air and charge inlet ports communicating by
means of a port A5 with the air supply passage c opening through
the throttle valve D to the mixing chamber for air and vapour E.
The exhaust discharges by the pipe F round the conical vaporising
chamber G and out at the exhaust pipe F'. The air supply is also
heated by the exhaust gases, and an air jacket is formed round the
exhaust pipe at H. The air, when heated, passes by way of the
passage i into the mixing chamber E, and the oil, which is forced
from the oil supply reservoir K by air pressure into the vaporiser,
is vaporised and passes into the mixing chamber by way of a
similar passage L, and there mixes with a further portion of hot
Oil Engines 455
air. A small portion of air passes through the vaporiser to
carry off the oil vapour, and this portion of air is heated also by
the exhaust gases. The engine is governed by throttling the
charge admitted by means of the throttle valve D operated from
the governor shaft M, and at the same time the oil supply is varied
with the air supply. This method of governing is not a good one,
and must result in a somewhat high consumption at light loads.
The difficulties too of maintaining the working surfaces of a plug
valve under the trying conditions operating in a gas engine have
prevented plug valves being used to any extent except for the
very smallest engines. The author is somewhat surprised that
the inventor of this engine (Mr. Butler) should have attempted to
use a plug valve under the vastly more difficult conditions of a
petroleum engine. To start the engine a small quantity of
benzoline is used, which is supplied until all the parts are heated
up sufficiently. An engine of this type was exhibited at the
Cambridge Show ; it was rated at 6 HP brake, the diameter of
the cylinder was 7^ ins., and the stroke \2\ ins. The speed was
declared to be 350 revolutions per minute. The weight of the
engine was 35 cwts. Owing to difficulties with the engine at the
Show, however, it was withdrawn from competition.
Weyman 6° Hitchcock's Oil Engine. — This engine resembles
the Hornsby and Robey engines in that the vaporiser is heated
by the heat of the explosions and exhaust products only. In it,
however, the gases are ignited by an incandescent tube raised to
incandescence by a separate lamp. The vaporiser chamber,
however, communicates with the cylinder by a valve, and so the
engine comes under this particular head. The oil supply is
pumped through a sight feed tube D to the top of the vaporiser,
as shown at fig. 224, where D is a sight feed tube and c the
vaporiser. This oil with a small proportion of air passes round
an annular passage, and the oil gradually vaporises as it falls and
diffuses into the air accompanying it. The oil charged with
vapour rises through a series of holes to a central chamber and
then passes through a vapour valve into the cylinder, where it
meets with an additional air supply. The ignition tube is heated
by an external lamp operated by a powerful air blast produced
from an air pump on the engine. Fig. 225 is an end elevation of
456
Oil Engines
this engine duly lettered with references printed underneath.
From this it will be seen that the engine is of somewhat complex
construction.
Tests and Oil Consumption. — An engine exhibited at the
Cambridge Show was declared as of 5 brake HP, the cylinder
was 6| ins. diameter by 13 ins. stroke, and the declared speed
was 250 revolutions per minute. On a three days' test the engine
developed a mean power of 6'2i brake horse and consumed
1*13 Ib. of oil per brake horse hour. The engine took from 14
to 1 7 minutes to start. At a full-power test lasting for two hours
FIG. 224 Weyman & Hitchcock's Oil Engine (part section).
A, cylinder ; B, combustion chamber ; c, oil inlet ; D, sight feed tube ; E, pump ;
F, main air supply ; i, lubricator.
the same engine developed 6-5 IHP, 473 brake horse on a mean
speed of 2597 revolutions per minute, and consumed '87 Ib.
of oil per IHP hour, and 1-19 Ib. per brake HP hour. At
half load the engine developed 2-58 brake horse ; the oil
consumed was 1*57 Ib. per brake horse hour. Running without
load at 207 revolutions per minute the engine consumed 277 Ibs
of oil per hour. Fig. 226 is a diagram from the engine.
Wells Brothers' Oil Engine. — Fig. 227 is an end elevation of
the Wells engine, showing the important parts. Professor Capper,
Oil Engines
457
in his report to the Royal Agricultural Society, describes it as
follows :
* There is but one rocking lever to actuate all the valves. It
is driven by a cam on the lay shaft, in opposition to a powerful
spiral spring. When running at normal speed, the spring draws
the lever home, closing the exhaust valve, and opening the vapour
FIG. 225 Weyman & Hitchcock's Oil Engine (end elevation).
#, side lever \ c, governor ; de, rocking levers working oil and air valves ; g, air inlet
pipe ; Q, oil reservoir for lamp j R, oil supply pipe to lamp ; s, air blast pipe ; T, air
pump; u, lamp reservoir ; w, oil pump; x, oil pump discharge ; Y, oil supply
pipe ; z, pet cock.
valve at the required moment. When running too fast, the hori-
zontal catch, which has been lowered, by the outward movement
of the valve lever, has not time to rise clear under the weight of
its inner end before the return of the vertical lever, which there-
fore is arrested, and no movement of the valves takes place.
The exhaust valve is then kept open, and the vapour valve being
458
OH Engines
closed, an idle stroke occurs, the oil valve at the same time emit-
ting a charge from the vaporiser. The oil valve is a rotating taper
plug, driven by a link off a rocking lever. A cavity in this plug
measures out a charge of oil at each vibration, and drops it upon
a heated diagonal plate, down which it runs and is vaporised. An
adjustment is provided by which the quantity of oil at each charge
can be regulated, and the valve box is filled by gravity from a
raised tank. This arrangement is secure against injury from dirt,
as anything that is small enough to pass into the oil plug would
simply fall to the bottom of the vaporising chamber, and there
Ib.pep A
alsol
/60
140
IZO
100
80
60
+0
20
/)
Sy. in.
(Lite
|\
\
\
\
\
\
I
N
v^
(
\
^s
^
— —
*^
^
"^^
^•^^1B
}
/ "2 '3 4
FIG. 226. — Weyman & Hitchcock's Oil Engine (diagram).
be retained. The lamp which heats the vaporiser is completely
inclosed in a cast-iron combustion chamber, the blast being sup-
plied by an air pump.' ' The makers claim that little, if any,
gasification takes place, as the vaporiser is water-jacketed, and so
not overheated. This view is to some extent upheld by the fact
that the cylinder works without lubrication, beyond that of
inclosed oil vapour.'
Tests and Oil Consumption. — An engine of this type was
exhibited at the Cambridge Show of a declared 4 HP nominal.
The cylinder was 8J ins. diameter, and 15 ins. stroke, the declared
Oil Engines
459
speed being 165 revolutions per minute. This engine gave on the
three days' test a mean power of 5*96 horse, and consumed ro6
Ib. of oil per brake horse hour. The engine was very easily
started, starting usually in from 10 to 17 mins. A full- power test
of two hours gave an indicated power of 7-3, and a brake power ot
6-46 horse, the oil consumption being -93 Ib. per IHP per hour
and i '04 per brake horse hour. The engine ran at an average
speed of 184 revolutions.
At half- power 3-52 brake
horse was given, and a
consumption of 1*59 Ib. of
oil per brake horse. Run-
ning without load the en-
gine used i '96 Ib. of oil per
hour at 165 revolutions per
minute, Fig. 228 is a dia-
gram taken from the Wells
engine.
Applications of Petro-
leum Engines. — Petroleum
engines have now been
applied, in addition to the
ordinary purposes for which
stationary engines are re-
quired, to the propulsion
of launches, and for ac-
tuating road carriages. Most
of the launch engines use
gasoline or other light oil,
and so present no peculia-
rities which need be studied here. It will be observed that the
author has not described any of the oil engines produced on the
Continent or in America. These engines are without exception
engines of the ordinary gas engine type using gasoline or other
light oils which require no special precautions, and indeed are not
interesting as bearing on the question of safe heavy oil engines.
The engines on the Continent and in America which use heavy oil
are those already described in this chapter or engines following
A, vapour valve ; c, horizontal catch ; D, vaporiser
door ; E, exhaust valve ; K, trip ; L, rocking lever;
M, oil supply cock ; N, oil supply chamber ; o, oil
supply pipe ; P, oil supply to lamp ; Q, automatic
explosion counter ; R, link working oil valve ; v,
vaporiser.
FIG. 227. — Wells Oil Engine
(end elevation).
460
Oil Engines
the same lines. Many ingenious details are used in the foreign
oil engines, but as yet British inventors appear to have taken the
lead in the task of devising means of utilising the safe lamp oils
of commerce. This probably is due to the somewhat severe legal
restrictions placed upon the sale and storage of such light and
inflammable oils as gasoline, benzine or petroleum spirit, restric-
tions which do not exist in the laws of America or France. The
principal engine used upon the Continent for marine purposes is
that of Daimler.
The Daimler engine is a small two-cylinder engine ; the two
160
140
120
IOO
80
60
40
20
O
FIG. 228 Wells Oil Engine (diagram).
cylinders incline at an angle of about 30° to each other, and the
connecting rods operate on a common crank pin. The front ends
of the cylinders are closed in, and the front ends act as air pumps.
The Otto cycle is performed by each piston, but each cylinder is
supercharged with air to a pressure of a few pounds above
atmosphere, the air being supplied from the front of the piston.
By this device a high average pressure is obtained, but light oil is
used so that no special vaporising arrangements are required.
The Daimler Motor Carriage. — The Daimler motor carnage has
come into considerable prominence in connection with the recent
trials of horseless carriages in France. The author has carefully
Oil Engines 461
examined one of these carriages, and finds that it contains one
of the ordinary two-cylinder Daimler light oil motors, which is
mounted with its crank shaft axis parallel to the length of the
carriage. The engine is started by a handle projecting from the
front of the carnage, which handle drives a spindle by pitch chain.
When the engine starts, it puts a stop out of gear and disconnects
the chain. The engine shaft gears into a friction clutch, which
can be drawn in and out to disconnect the engine from the
carriage wheels. The back wheels of the four-wheeled carriage
are driven by a shaft carried across the centre of the carriage, and
operated from the engine-driving spindle by bevil wheel and
opposing bevil wheels so geared as to form a reversing arrange-
ment by engaging on one x>r other side of the engine bevil wheel.
The spindle carrying the engine bevil wheel is geared to the
engine shaft by means of change wheels of the ordinary pinion
and spur wheel type, four sets of wheels being provided which
may be geared one pair at a time to give four different speeds
without varying the speed of the engine. The two front wheels
are steering wheels, and are operated by a lever somewhat like
that used to steer a Bath chair. The rear driving wheels of the
carriage are geared to the cross shaft by pitch chains. The en-
gine uses light oil contained in a small reservoir in front of the
driver. The mixture is ignited by means of two platinum tubes
heated to incandescence by an oil flame of the Bunsen type. The
engine when started runs at a constant speed, and the whole of
the operations of the carriage are performed by means of levers,
clutches, change wheels and brakes. In the author's opinion
this carriage, ingenious as it is, will not find much use in England.
A carriage, however, using heavy oils and overcoming the diffi-
culties would probably be very successful.
.462 Oil Engines
CHAPTER III.
THE DIFFICULTIES OF OIL ENGINES.
THE reader will have observed from the description of thirteen
different examples of oil engines given in the preceding chapter,
and the details of oil consumption and efficiency, that the oil
engine is not so economical from a heat engine point of view as a
gas engine ; that is, the oil engine so far, for a given number of heat
units entrusted to it as oil, does not convert so large a proportion
of those heat units into indicated work as a gas engine. It is to
be remembered, of course, that as yet engineers have had little
experience in oil engines, as compared with gas engines, and that
probably with further development of detail the heat efficiency of
the oil engine may yet be considerably increased. The lower
efficiency at present obtained is due to certain difficulties peculiar
to the oil engine, which do not occur in the gas engine. These
difficulties are present to some extent in all the three types of
engine, but in some types to a greater extent than in others. In
the earlier engines ignition presented a formidable difficulty, which
was overcome by the use of the electric spark. Electric methods
of ignition are very objectionable whether used in gas or oil
engines ; so objectionable, indeed, that no gas engine at present
manufactured in Britain uses an electric igniter. . Electric igniters
require a battery, an induction coil and insulated points, or an
electro-magnetic device, and insulated points with a contact-
breaking contrivance. Either of these forms can be made to work
quite well in an engineer's hands or in the hands of anyone used
to batteries and dynamos, and willing at the same time to devote
considerable attention to keeping the apparatus in order. The
public in this country, however, who use gas and oil engines are
•very liable to allow electric contrivances to get out of order, and it
The Difficulties of Oil Engines 463
has always been the author's opinion that any engine with an
electric igniting device, even if good in other respects, would not
attain extended use in Britain. Curiously enough this objection
does not seem to weigh much with the Continental public or with
the American public, as many engines are sold on the Continent
and in America which use electric igniting devices. The nature
of safe burning oil made it very difficult to use either a flame
device for igniting or an incandescent tube for that purpose. It
was by no means easy and evident to see in what way safe heavy
oil could be treated to give a smokeless heating flame of the
character necessary either for flame ignition or incandescent tube
ignition. The production of the type of lamp described at
page 431 gave, however, an easy means of producing a smokeless
heating flame, and so at once made it possible to use that simplest
of all igniting devices, the incandescent tube. In the author's
opinion the incandescent tube igniter is by far the best adapted
both for oil and gas engines, and now that simple lamps have
been produced to give a smokeless flame the incandescent tube
is bound to displace all other forms of ignition for oil engines.
The type of lamp referred to also seems to the author to be the
best yet proposed, as it gives a powerful smokeless flame from
heavy oils, and that without the use of the troublesome air blast.
In many of the earlier forms of the engines described, an air
blast was used somewhat in the manner shown at fig. 194 and
described as the Griffin oil sprayer lamp. So far, then, as the
present engine is concerned, the difficulty of igniting may be con-
sidered as thoroughly overcome in a manner which is not likely to
be greatly improved upon, and so far as the ignition is concerned
there is nothing which prevents greater economy from being
obtained. The difficulties which prevent immediate improvement
in economy are to be found in all cases in the methods of vapo-
rising. Some inventors claim to gasify wholly or partly the oil
which is sent into the engine cylinder, and others claim that the
oil so sent in is merely vaporised and not gasified. The author
has examined all the standard types of oil engine now in use, and
from his own experiments he is convinced that in not one of the
engines does any real gasification take place ; in all the thirteen
engines referred to the oil is vaporised, not gasified. In some of
464 Oil Engines
the engines the oil may be ' cracked ' to a small extent, so that
the vapours produced are those of lighter hydrocarbons than were
present in the original oil, but no cracking which can take place
in any of these engines is anything like sufficient to carry decom-
position far enough to produce gas instead of vapour.
These engines have been classified by reference to the method
of vaporisation peculiar to each, and each type, although it
presents a satisfactory solution of the vaporising difficulty, in-
volves additions to the ordinary gas engine cycle which are
accompanied by characteristic limitations or disadvantages.
Thus the first type of oil engine using safe oil, 'engines in
which the oil is subjected to a spraying operation before
vaporising,' is also first in the order of invention, and it naturally
presents the most complex solution of the vaporising difficulty.
In this type of engine, represented by the engines of Messrs.
Priestman and Samuelson, the whole air supply of the engine is
passed through a heated chamber, and according to Professor
Unvvin, in one of his tests, the air leaving this heated chamber
before it enters the engine cylinder is raised to a temperature of
287° F. The chamber is heated by the exhaust gases from the
engine, which gases in this experiment were at a temperature of
600° F. ; the oil to be vaporised is injected into the heating
chamber, by means of a smaller quantity of air, in a state of very
fine spray, as has been described in the preceding chapter. The
whole of the oil used is therefore mixed with the air passing
into the engine in minute particles of spray, each of these minute
particles of sprayed oil being surrounded by an atmosphere of air
at a temperature of nearly 290° F. Each oil particle thus has an
ample atmosphere of air surrounding it at this high temperature,
and thus each particle rapidly evaporates and passes from the
state of spray to the state of oil vapour uniformly diffused
throughout the air charge. The device produces very perfect
vaporisation, but it has the great disadvantage that the whole of
the inflammable charge entering the cylinder becomes heated to
290° F. while still at atmospheric pressure. From this it follows
that upon compressing the mixture in the cylinder the temperature
of compression rises to a much higher point for a given pressure
than is the case with a gas engine charge working at that pressure.
The Difficulties of Oil Engines 465
In the gas engine the charge enters the cylinder at atmospheric
temperature, and is only heated to a slight extent by the inclosing
walls. In the case of the oil engine the entering charge is heated
to begin with, and is likely to absorb further heat from the piston
as it enters. This has the effect of reducing the total weight of
charge present in the engine cylinder at each stroke, and therefore
it reduces the average available pressure to be obtained from the
engine. In the Priestman engine, for example, the best result
obtained in Professor Unvvin's experiments give only a mean
available pressure of 45 Ibs. per square inch throughout the stroke
with a compression pressure of 27 Ibs. It is worth noting that a
compression pressure of 27 Ibs. was used in a Priestman engine at
a time when the usual compression pressure in gas engines ranged
from 40 to 50 Ibs. This low pressure necessarily involves less
economy than the high pressure, and the reason why a low pressure
is adopted is found in the fact that at higher pressures an oil engine
operating by the spray method is very liable to premature ignitions.
This is partly because of the ready inflammability of a mixture of air
and heavy oil vapour, and partly because of the higher tempera-
ture of compression due to the preliminary heating of the whole
charge in the vaporiser. An oil and air charge is much more
liable to spontaneous ignition during compression than a gas and
air charge, and the preliminary heating of the whole charge to
about 80° F. above the boiling point of water necessarily increases
the temperature obtained by compression, and this higher tem-
perature tends to make the charge ignite prematurely.
It is interesting to note that with Daylight oil Professor
Unwin found a pressure of compression of 35 Ibs. per square inch
more suitable than 27 Ibs. This is doubtless due to the fact
that lighter oils such as Daylight oil when vaporised approxi-
mate more nearly to the gaseous condition, and are therefore less
easily subject to premature ignition than the heavier oils.
One difficulty, therefore, caused by the spray method of
ignition lies in the limitation of the weight of the charge by pre-
liminary heating, from which follows the production of a lower
average pressure ; another difficulty lies in the limitation of the
compression pressure due to the property of spontaneous ignition,
which is made more marked by the preliminary heating. These
H H
466 Oil Engines
difficulties prevent the attainment of greater economy by the first
method of vaporising.
This method, however, presents other difficulties of a practical
kind. Thus a large volume of charge is formed in the vaporiser
in explosive proportions, and the whole of this charge is liable to
be ignited in the event of a back explosion from the engine
cylinder while the charging stroke is proceeding. This is a
serious difficulty, and has caused in gas engines the practical
abandonment of all engines in which a reservoir of gas and air
is used to feed the engine cylinder.
A further difficulty occurs in governing the engine. As the
exhaust gases are used to heat the vaporiser, by means of a
jacket surrounding the vaporiser chamber, it follows that the
ordinary method of governing practised in the gas engine is
inapplicable. Messrs. Priestman accordingly produce ignitions
under all circumstances, whether their engine be light or loaded ;
that is, instead of cutting out impulses by stopping off the oil
supply completely, they reduce both oil and air supply simul-
taneously, and by so doing reduce the pressure at which the
cylinder is filled with inflammable mixture before compression
begins. The proportion of oil and air admitted is kept as nearly
as possible constant, but the compression pressure is continuously
reduced and produces weaker and weaker impulses. This is
clearly shown in the diagram, fig. 191, page 41 7, where the full-power
diagram is shown by a heavy black continuous line, the half-
power diagram by a dotted line, and the diagram produced when
the engine is running light by a thin full line. This method is by
no means an economical one, and results in a heavy consumption
of oil even at light loads. In Professor Unwin's test, for example,
it was found that the engine consumed 6| Ibs. to 7 Ibs. of oil per
hour when working at full power ; and when working giving no
power at all, only driving itself at full speed, the oil consumption
was still 5 Ibs. This of course is a very poor result, the engine
using almost as much oil without load as at full load ; in fact in
Unwin's test there was no difference in oil consumption between
half power and no load at all. This is a difficulty, however,
which is common to all gas engines as well as oil engines in which
tbe charge is supplied from an intermediate reservoir of consider-
The Difficulties of Oil Engines 467
able capacity. With such a reservoir it is evident that the govern-
ing cannot be effected by simply cutting off the gas supply, as
if the governor had acted the engine would still receive one or
more charges and give one or more impulses after the governor
had signalled that it was running too fast. In the same way,
when the governor put the gas or oil supply on fully again, the
engine had to make several revolutions before the mixture reached
the cylinder. This causes serious irregularity as well as loss of
gas due to imperfect mixture at the time of governing.
Messrs. Samuelson endeavour to avoid this difficulty of governing
by holding closed the exhaust valve, and keeping the inlet valve
closed. In this way the piston expands and compresses the ex-
haust gases without taking any charge from the vaporiser. This
method of governing, however, is not satisfactory, because of the
difficulty of keeping a constant charge in the vaporiser while
the engine is governing. A further difficulty is due to the fact
that when the explosions cease exhaust gases no longer pass
round the vaporiser, and the temperature rapidly falls, so that it is
liable to get much too cool for the effective performance of its
work. This difficulty affects the Priestman engine to a lesser
extent because of the continuance of the explosions, but even
there the temperature of the vaporiser falls considerably when
the engine is running with light loads or no load at all.
In the author's opinion the spray method of vaporising as
hitherto carried out is the least satisfactory of all the methods of
vaporising, and the second and third methods present consider-
able advantages over it, both in simplicity and effective operation.
The second type of oil engine comprises ' engines in which
the oil is injected into the cylinder and vaporised within the
cylinder.' The engines constructed under this type repre-
sented by the Hornsby, the Robey, and the Capitaine engines,
distinctly advance upon the spray method of vaporising, but they
also present difficulties of a somewhat formidable kind. The
Hornsby- Ackroyd engine, for example, tested at the Royal Agri-
cultural Society's Show gave a mean available pressure throughout
the stroke of only 29 Ibs. per sq. in. This of course necessitates a
large cylinder for a given power. The mean pressure, it will be
observed, is lower than that given by Class I., and this although
H H 2
468 Oil Engines
the compression pressure is much higher. The Hornsby engine
gave a compression pressure of 50 Ibs. per sq. in, and should have
given a higher average pressure than that of Class I. but for
certain peculiarities which have now to be considered. In this
type of engine the walls of the combustion space are allowed to
attain a temperature of nearly 800° C., sufficient to cause effective
vaporisation and also to allow of ignition when compression is
completed. The air charge entering the cylinder in the Hornsby
engine does not pass through the combustion space, but passes
directly into the water-jacketed cylinder. The air, therefore, is
not heated up by passing through the vaporising chamber ; the
exhaust gases of the previous explosion, however, are kept at a very
high temperature in the combustion chamber, which chamber
is cut off to a certain extent from the main cylinder by the
bottle neck seen at fig. 195, page 421. The cause of the low
available pressure, however, is not due to heating of the air while
entering, the cylinder, as that heating only occurs to a slightly
greater extent than in the case of the gas engine. The real cause
of the low average pressure is imperfect mixing of the air charge
with the oil vapour. The oil is injected into the combustion
space A during the charging stroke of the piston. It rapidly
evaporates because of its contact with the highly heated walls,
and it diffuses among the hot exhaust gases contained in the
combustion space. As there is, however, very little oxygen pre-
sent in that space at the moment of vaporising, there is no danger
of premature ignition. Ignition is not possible until air has been
forced from the cylinder through the bottle neck to supply
oxygen sufficient for the combustion of the vaporised oil. As the
compression proceeds, more and more air mixes with the vapo-
rised oil, and sufficient oxygen is forced into the combustion
chamber to properly burn the oil vapour charge. A certain
amount of oxygen, however, and nitrogen remains outside the
combustion chamber in the space between its limits and the
piston, and so the cylinder is not filled with a uniform inflam-
mable mixture. The mixture produced within the combustion
chamber is also less perfectly mixed with the air than the charge
in a gas engine cylinder, and accordingly to insure complete com-
bustion of the whole charge, a much larger proportion of oxygen
The Difficulties of Oil Engines 469
is necessary than in the gas engine. The average pressure of the
explosion is thus considerably reduced.
The reduction of average pressure would not matter much if
the only requirement were a larger diameter of cylinder ; that is, an
increased diameter without corresponding increase of the strength
of the crank, connecting rod, and engine frame ; unfortunately,
however, in the case of an oil engine or a gas engine the effect of
a double charge has always to be well kept in mind. Such a
double charge would raise the maximum pressure to an unsafe
point for a given diameter of cylinder unless the parts were made
sufficiently strong to resist this possible contingency. In the oil
engine, for example, an explosion might be missed and a double
charge of oil vapour would be left in the cylinder, and so the maxi-
mum pressure of the next explosion greatly increased. Engines
of Class II. have, therefore, large cylinders and heavy parts in pro-
portion to the power developed by them. Their economy also is
not proportional to the compression pressures used.
The governing difficulty is also much felt in this type of
engine. Here it is possible to stop the oil supply and cut out
explosions just as in the case of a gas engine, but the effect of this
is to cause the walls of the combustion space to be rapidly cooled
down at light loads. Most of the engines of this kind work well
at full or intermediate loads, but at light loads the combustion
space walls may become so cool that ignition fails and the engine
stops. Messrs. Hornsby have got over this difficulty to a very
great extent, but it is a difficulty which is quite formidable in this
type of engine. If the combustion chamber be so arranged and
shaped that its walls are sufficiently hot when the engine is running
without load, they are very apt to be overheated at full loads.
The skill of the makers of these engines is well shown in pro-
portions calculated to keep the combustion space walls hot, and
yet not too hot.
The fundamental idea of this type of engine is extremely
fascinating and simple, but considerable complexities arise in
carrying it into effect, which greatly detract from the advantages.
In the author's opinion this type of engine will always be
somewhat heavy and large for the power developed, as- it is
difficult to see how greater average pressures are to be obtained,
470 Oil Engines
or how greater economies are to be expected by reason of any
modifications of the type.
The third type of oil engine comprises ' engines in which the
oil is vaporised in a device external to the cylinder, and intro-
duced into the cylinder in a state of vapour.' Engines of this
class, in the author's opinion, furnish the simplest and most effec
tive solution of the problems involved in oil engine construction.
Even this class, however, presents two divisions. The first
division includes the engines of Messrs. Crossley Brothers, and
Fielding & Platt. In these engines oil is injected into a heated
vaporiser consisting of eicher a series of tubes or a series of
tubular passages. These tubes or passages are heated by the
waste heat of the oil lamp used for the incandescent tube. The
oil is injected at one end of the series of passages together with a
small quantity of air, and a small further quantity of air is heated
up by an air heater before reaching the oil ; this hot air passes
through the vaporiser part of the tubes, and evaporates the oil
and carries a charge into the engine cylinder in a state of
vapour. The main air charge enters the cylinder by a separate
valve, so that only a very small part of the air charge is heated
and passed in with the oil. By this arrangement the engine
cylinder itself and all the surfaces in contact with the charge
are water-jacketed, just as in the case of the gas engine. The
oil vapour and heated air entering at a port mix with the
cold air entering at a separate valve, and no doubt some
little precipitation of the oil vapour will occur because of
the cold air impinging upon the hot air saturated with in-
flammable vapour. This precipitation, however, will be in the
state of very fine mist indeed, and on the compression of the
charge the rising temperature of compression will speedily cause
the vapour to be formed again. This method of vaporising has
the advantage that the air charge is heated up to the smallest
possible extent consistent with forming an explosive charge by
means of heavy oil. The compression can thus be increased to a
greater extent than in the first two classes without danger of
premature ignition, and so much higher average pressures are
rendered possible. Accordingly we expect to find a higher
average pressure in this engine than in the others. Messrs.
The Difficulties of Oil Engines 471
Crossley obtained 72 Ibs. per sq. in. mean pressure with an ex-
plosion pressure of 225 Ibs. and a compression pressure of 65 Ibs.,
while Messrs. Fielding & Platt obtain a mean pressure of 63 Ibs.
with a compression pressure of 40 Ibs. This method of operation
also has the advantage that it allows of the usual gas engine mode
of governing, viz. by cutting out explosions. That the governing
is effective and economical is seen from the fact that a Crossley
engine which used 9-9 Ibs. of Russoline oil per hour, running
at full load, only used 2-53 Ibs. per hour running at full speed
without load, both figures including the oil for operating the
heating lamp. The Crossley engine tested was rated at 7^ HP.
A 3-horse engine tested by Messrs. Fielding & Platt, which con-
sumed 475 Ibs. of Russoline oil per hour at full load, ran without
load on i -3 Ib. per hour. These results show governing almost if
not quite presenting the same proportional economy as a gas
engine.
The second division includes the engines of Messrs. Tangye,
Campbell, the Britannia Co., Clarke, Chapman & Co., Weyman
& Hitchcock, and Wells Bros., and in these engines in all cases
except one (Clarke, Chapman & Co.) the whole air charge of the
engine passes through the vaporiser on its way to the cylinder.
This method of operating as carried out by Messrs. Tangye and
Campbell has certainly the advantage of great simplicity, but it
appears to have a disadvantage of less perfect vaporisation than
is given in the first division. At least a comparison of the oil
consumption of the different engines seems to point to this. For
instance the Crossley and Fielding & Platt's oil engines respec-
tively consume '82 and -90 Ib. of Russoline oil per BHP hour,
while the Campbell, Britannia, Wells, Weyman & Hitchcock
engines consume respectively 1*12, i'68, 1*04, and 1*19 Ib. of
oil per BHP hour. The engines of the second division thus
consume uniformly more oil per BHP hour than those of the first
division.
In the author's opinion this is partly caused by the fact that
the whole air charge is drawn through the vaporiser, and partly
by the fact that in all of these engines the explosion pressure has
free access to the vaporiser up to the inlet valve. By drawing
the whole of the air charge through a vaporiser with no prelimi-
47 2 Oil Engines
nary heating or only a slight preliminary heating, the temperature
of the^air is so low that it does not assist in any way the vaporising
of the charge, but rather retards it. As pointed out in Chapter I.
of this Part of the book, air can only take up oil vapour suffi-
ciently to saturate it at the particular temperature of the air ; and as
the tension of oil vapour is very low at the temperature of the
atmosphere, the air does not really help in vaporising, but
rather tends to condense the vapour formed by the hot walls of
the vaporiser. The oil, therefore, which is taken into the
cylinder is taken in partly as vapour and largely as a somewhat
heavy spray. This heavy spray readily falls on to the walls of the
cylinder and produces a less perfect charge.
The fact of keeping the vaporiser open to the explosion
right up to the inlet valve has the same effect in an oil engine as
it would have in a gas engine ; that is, it increases the port sur-
faces so much as to seriously cool the flame of the explosion
when the explosion occurs. These two causes are, in the author's
opinion, the principal causes of the higher consumption of the
second division of this class.
To make this type of vaporiser effective the air would require
to be heated to a considerable temperature before entering the
vaporiser, and this would of course introduce the difficulties
which have been already referred to in discussing Class I. A
valve, it is true, might be placed between the explosion port and
the tubular or passage port of the vaporiser, and this would un-
doubtedly improve the economy while running loaded, but it
would also increase the difficulty of effective governing. This
type of engine as described is readily governed, and very high
economies are obtained running without load. To make the
comparison more readily evident, the author has prepared the
table on page 473, which contrasts the leading facts connected
with the three classes of engine.
Oil Engine Improvements. — The reader must not suppose that
in the preceding discussion the author is in any way under-
valuing the great progress which has been made in oil engine
construction. Greater improvements are to be made in oil
engines than in gas engines, but inventors are rapidly overcoming
all the difficulties, and the oil engine of to-day is a very effective
The Difficulties of Oil Engines
473
COMPARISON OF OIL ENGINES.
CLASS I.
CLASS II.
CLASS III
Div. I.
CLASS III.
Div. II.
_i • i -^ __
Oil consumption )
per BHP hour ]
'95 lb.
•98 lb.
•82 lb.
1-12 lb.
1-68 lb.
i'o4lb.
1*19 lb.
Oil consumption )
per IMP hour j
•86 lb.
•8 i lb.
•73 lb.
'93 lb.
1-25 lb.
o'93 lb.
•87 lb.
Mean available 1
pressure . . )
45 lb.
29 lb.
72 lb.
65-5 lb.
47'3 lb.
49'61b.
46-1 lb.
Explosion pressure
130 lb.
II. lb.
225 lb.
200 lb.
i55 lb.
135 lb.
145 lb.
Compression )
pressure . . }
27 lb.
50 lb.
65 lb.
40 lb.
45 lb.
32 lb.
38 lb.
j
Power of engine 7 BHP , 8 BHP
7k BHP
4-8 BHP
6-2 BHP
6-5 BHP
4'7 BHP
Name of maker . Priestman
Hornsby
Crossley
Campbell
Britannia Co.
Wells
Weyman
Weight . . I 36 cwt.
40 cwt.
32^ cwt. | 27 cwt.
33 cwt.
1
36^ cwt. !
26 cwt.
and reliable machine. It is idle to deny, however, that further
improvements are possible, and the author's object is to point out
the difficulties as clearly as possible in order to aid inventors in
working on correct lines. Improvements in vaporisers will pro-
bably take the form of obtaining a very complete cracking of the
oil, tending to charge the cylinder with vapours of lighter oils
than those introduced into the vaporiser. This process will
supply the engine with oils capable of withstanding higher com-
pressions than are at present used without premature ignitions.
Every effort will be made also to keep all parts of the cylinder
cool and water-jacketed as with the gas engine. The heating
lamp is also capable of improvement, and efforts should be made
to produce a flame of the Bunsen or smokeless type, giving less
noise than at present. Oil engine inventors will pay more atten-
tion to the now well-understood principles of gas engine design,
and will accordingly do away as much as possible with all long
ports or increased surfaces in contact with the flame of the
explosion.
APPENDIX I
ADIABATIC AND ISOTHERMAL COMPRESSION OF DRY AIR.
{Professor R. H. Thurston, Journal of Franklin Institute, 1884.)
'One hundred volumes of dry air at the atmospheric mean temperature
•of 15-5° C. and 147 Ibs. per square inch undergo change of volume
without loss or gain of heat. The temperatures and volumes corre-
sponding to various pressures are given. Also the volumes at the
various pressures if the temperature remained constant at 15-5° C.
Absolute pressure in
Ibs. per sq. inch
I
Temperature of
compression in
Centigrade degrees
Volume at
temperature and
pressures preceding
Volume if
temperature constant
at 15*5°
*47
15 '5
100 -0
15 "0
17-26
98-58
98-00
20*0
42 -6o
80-36
73'50
25-0
64-76
68-59
58-80
30-0
82-10
60-27
49-00
35 'o
98-38
54-oi
42*00
40 -o
113-86
49-13
3675
45 'o
126-54
45'18
3^67
50-0
138-96
4i '93
29*40
55-o
60 *o
iSo-53
161-38
39-19
36-84
26*73
24-5°
65-0
171-61
34-80
22-62
70-0
181*29
33-02
2I*OO
75 'o
190-49
3i-44
I9*6o
80 -o
199-26
30-03
18-38
85-0
207 '66
28-77
17-29
90*0
21471
27*62
16 '33
95 'o
223-45
26-58
I5H7
100 -o
230-91
25-63
14*70
125-0
264-66
21-88
11-76
150*0
293-91
19-22
9'8o
175 '0
319-87
17-23
8'40
200 '0
343'3i
IS'6/
7'35
225-0
36471
14-41
6-53
250-0
4H-57
13-38
5-88
300-0
420-34
n-75
4-90
400-0
480-76
9".S8
3'9o
5CO-0
S31'21
8-17
2*94
600 -o
574-93
7-18
2 '45
700-0
60374
6-44
2'10
800-0
648-80
586
1-84
900-0
68o-85
5-39
1-63
1000
710-49
5-00
i '47
2000
929-67
3-06
074
The Gas Engine
ANALYSIS OF COAL GAS.
(T. Chandler, Watts 'Diet.' Supp. 3, Part i.)
Heidelberg
Bonn
Chemnitz
London
Ordinary
Cannel
coal gas
gas
vols.
vols.
vols.
vols.
vols.
Hydrogen, H . .
44-00
39-80
46-00
27-70
Marsh gas, CH4 . .
Carbonic oxide, CO .
38-40
573
43'12
4-66
4 '45
39 '50
7 '5°
50-00
6-80
Heavy hydrocarbons
Nitrogen, N . . .
Carbonic acid, CO2 .
7-27
4 '23
o'37
475
3-02
4-91
1-41
i -08
3-80
0*50
13-00
0*40
O'lO
Water vapour, H2O .
—
2 '00
2'00
ANALYSIS OF LONDON COAL GAS.
(Humpidge. )
Sample (A)
Sample (B)
vols.
vols.
Hydrogen, H
Marsh gas, CH4 .....
Carbonic oxide, CO .....
50-05
32-87
12-89
51*24
35 '28
7-40
Olefines
3-87
3-56
Nitrogen, N ......
2 '24
Carbonic acid, CO^ . . • .
0-32
0-38
ANALYSIS OF BERLIN AND NEW YORK COAL GAS.
Berlin
New York Municipal
Gas Light Co.
vols.
vols.
Hydrogen, H
Marsh gas, CH4 '
Carbonic oxide, CO .
4975
32-70
o'54
3° '30
24-30
26-50
Ethylene, C2H4 .
4"6i
15-00
Nitrogen, N . . .
0-68
2-40
Carbonic acid, COo
2-50
I -00
Oxygen, O
0-22
o'5°
.
Appendix I
477
ANALYSIS OF NATURAL GAS FROM GAS WELLS IN PENNSYLVANIA.
( Watts' 'Diet, of Chemistry,' Supp. 3, Part 2.)
Burns Butler
Co. 'swell
Lechburgh
Westmoreland Co.
Harvey
Butler Co.
vols.
vols.
vols.
Carbonic acid, COo
°'34
o'35
0-66
Carbonic oxide, CO
trace
O'26
—
Hydrogen, H
6'io
479
13 'So
Marsh gas, CH4 .
75 '44
89-65
So'ii
Ethylene, C2H4 .
l8'I2
4 '39
572
Hydrocarbons composition
not stated ;
—
o's6
—
478
The Gas Engine
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The Gas Engine
TABLE III. CALCULATED FROM TABLE I.
Oxygen or air required for complete combustion of\ vol. of each of the
following gases.
Town
Oxygen
Air
Vol. of products
vols.
vols.
Edinburgh . ' .
'55
7-40
8-25
Glasgow . . ' .
'44
6-85
7-65
St. Andrews . .
'49
7-08
7-88
Liverpool
'37
6-52
5'45
Preston .
•28
6'io
6-88
Nottingham .
'SO
6-17
6-14
Leeds . .
•40
6-67
7 '47
Sheffield . .
•36
6-49
7-28
Birmingham
•09
5'i9
6-08
Bristol
°2Q
6-16
6'<x
London —
?
v J7O
Gaslight & Coke Co.
'2O
576
6-53
South Metropolitan Co.
'*5
5 '47
6 '20
Redhill
•22
5-82
6-58
Gloucester . • .
•25
5 '94
6*69
Newcastle-on-Tyne .
•*s
5 '49
6-24
Newcastle-under-Lyme .
'2O.
572.
6-48
Brighton
•18
5-62
6-36
Southampton . . .
•17
5-56
6 '29
Ipswich .....
•18
5-63
6-31
Norwich
•18
5-63
6 '39
LIST OF BRITISH GAS AND OIL ENGINE
PATENTS
FROM THE YEAR 179! TO 1897 INCLUSIVE.
When patents are communicated, the names of the communicators are printed
within parentheses.
1791.
NO.
1833. Jonn Barber. — Using inflammable air for the purpose of producing
„ .; motion.
1794.
1983. Robert Street. — Method of producing an inflammable vapour force by
means of fire, flame, &c.
1797.
2164. James Glazebrook. — Working machinery by means of the properties
of air.
1801.
2504. James Glazebrook. — Power from mixtures of air, such as hydrogen,
nitrous air, &c.
1817.
4179. J. C. Niepce.— Propelling vessels by explosive gases.
1823.
4874. Samuel Brown. — Effecting a vacuum by flame, and thus producing
power.
1826.
5350. Samuel Brown. — Improvements in his former patent, No. 4874.
5402. E. Hazard. — Preparing mixtures of vapours with air, and exploding
them to obtain motive power.
1833-
6525. L. W. Wright. — Explosive engine. Carburetted hydrogen and air are
forced into reservoir and exploded.
I I
482 The Gas Engine
1835-
NO.
6875. J. C. Douglass.— Explosion engine.
1838.
7615. W. Barnett. — Obtaining motive power from inflammable gases by
compression and explosion.
7871. Byerley & Collins. — Using of steam or gas, or both combined, with
the hydrostatic paradox.
l839.
8207. H. Finkus. — Motive power obtained either by explosion or exhaustion.
1840.
8644. Henry Pinkus. — Explosion engine.
1841.
8841. James Johnson. — Motive power obtained by the explosion of oxygen
and hydrogen.
1843-
9972. Joseph Robinson.— Engine driven by inflammable gas or vapour.
1844.
10404. J. W. B. Reynolds. — Gas or pneumatic locomotive engines ; explosion
of a mixture of gas and air.
1846.
11072. Samuel Brown. — Improvements in gas engines and in propelling car-
riages and vessels (no specification enrolled).
11245. W. Cormack. — Motive power is obtained by contraction and rare-
faction.
1850.
13302. E. C. Shepard. — Explosion engine.
1852.
940. N. Seward. — Motive power. Gunpowder.
979. W. Quaterman (provisional only). — Motive power by gaseous matter.
14086. Samuel Haseltine. — Improvements in engines to be worked by air or
gases (no specification enrolled).
14150. A. V. Newton. — Gas engine.
1853-
362. Robert Roger (provisional only). — Obtaining motive power by ex-
plosion.
515. R. L. Bolton. —Motive power is obtained from the explosion of gases.
Appendix II 483
NO.
1248. E. J. Schollick. — Water is decomposed by electric currents into its
component gases, which gases pass into a cylinder, and are exploded
by another electric apparatus.
1577. Joseph Webb (provisional only). — Improvements in obtaining and
applying motive powers (gas and electricity) by explosion.
1648. Fabian Wrede. — Improvements in gas and air engines.
1671. A. Carosio (provisional only) — Producing explosive gases electro-
magnetically.
1854.
191. James Anderson (provisional only) — Motive power obtained by air,
gases, or vapour.
549. J. C. Edington (provisional only). — Mixture of carburetted hydrogen
and air, exploded in a cylinder.
1072. Barsanti & Matteucci (provisional only). — Apply the explosion of
gases as a motive power (atmospheric engine).
I855-
339. T. B. Blanchard. — Motive power from combustion.
562. Alfred V. Newton. — Improvements in engines worked by explosive
mixtures.
ion. Henri Balestrino (provisional only). — Improvements in obtaining
motive power by aid of explosive gases.
1856.
1807. C. J. B. Torassa. — Improvements in obtaining motive power by aid
of explosive gases.
1857-
1655. Barsanti & Matteucci — Improvements in obtaining motive power
from explosive gases.
1754. J. S. Rousselot — Improved method for obtaining motive power, and
engine for applying the same.
2408. J. E. F. Luedeke — Motive-power engine (explosion).
1858.
969. W. Clark Burnt air motor.
996. C. D. Archibald — Treating air or gases for purposes of motive power.
2648. R. Nelson. — Vacuum obtained by ignited hydrocarbon fluids.
1859-
784. T. M. Meekins Production of motive power, and projectile and ex-
plosive force (provisional protection refused).
1227. J. Nasmyth. — Improved apparatus for obtaining and applying motive
power.
I I 2
484 The Gas Engine
NO.
1345. P. Gambardella Obtaining motive power from mixture of hydrogen
and oxygen, exploded by electric spark.
2767. J- Anderson — Coal is partially burned and wholly distilled in a furnace
into which the proper quantity of air is introduced.
i860.
335. J. H. Johnson — Improvements in obtaining motive power.
615. Pierre Hugon. — Gas and air exploded in bent tube over water.
878. Michael Henry — An explosive mixture ignited by the electric spark.
1585. H. F. Cohade. — A mixture of air and gas is exploded in a chamber
furnished with a valve to produce pressure.
2743. W. E. Newton — Heating apparatus consists of a burner from which
hydrogen under pressure escapes and is ignited by an electric spark.
2902. Pierre Hugon. — Improved method for igniting explosive gaseous com-
pounds.
1861.
107. J. H. Johnson. — Improvements upon the reciprocating gas motive
power engine, No. 335/1860.
166. Jean B. Pascal. — Application of inflammable gas, produced by decom-
position of steam, to explosion engine.
3270. W. E. Newton — Force generated by the explosion of a mixture of
atmospheric air and hydrogen.
1862.
2143. C. W. Siemens (provisional only). — Mixed air and gas are admitted
into the working cylinder and ignited by electricity.
3108. Jacques Arbos. — A gas engine with apparatus for generating gas,
forming one apparatus.
1863.
653. Pierre Hugon. — Explosive force of the gaseous mixture acts upon an
intermediate column of water, and thus indirectly upon the piston.
1449. W. Clark — Effecting the combination of oxygen with the fuel, and
their intermixture with the burning products of combustion, causing
motive power.
2098. R. A. Brooman. — Improvements in air and gas engines.
1864.
1099. M. P. W. Boulton — In connection with the mode of working steam
and caloric engines to employ that portion of heat which is generated
by combustion of the fuel.
1173. F. H. Wenham Engines worked by explosive mixtures.
Appendix II 485
NO.
1288. J. E. Holmes (provisional only) — Vacuum by explosion.
1291. M. P. W. Boulton. — Improvements in engines worked by heated air
or gases mixed with steam.
1599. B. F. Stevens Applying petroleum vapour mixed with air.
1636. M. P. W. Boulton Improvements in obtaining motive power from
aeriform fluids.
3044. M. P. W. Boulton Improvements in heating aeriform fluids by in-
jecting some substance in a state of fusion (chlorides, &e.).
1865.
501. M. P. W. Boulton. — Improvements in obtaining motive power from
aeriform fluids and from liquids.
827, M. P. W. Boulton Obtaining motive power from aeriform fluids and
liquids.
905. John Pinchbeck (provisional only) — The connection of the exhaust
pipe of the cylinder with a condensing chamber of engines worked
by explosion of air and gas.
986. Pierre Hugon — Effecting the combustion or explosion of gases by
means of slide valves carrying gas burners supplied with gas under
pressure.
1915. M. P. W. Boulton — Improvements in obtaining motive power when
heated air or aeriform fluid is employed.
1992. M. P. W. Boulton. — Method for utilising a larger portion of heat.
2600. W. E. Gedge Expansion engine.
1866.
27. T. T. Macneil (provisional only). — Motive power is produced by means
of a receptacle containing incandescent fuel into which is forced
the requisite air for combustion.
181. W. Clark (provisional only). — Motive power, heated gas or air.
434. C. D. Abel. — The explosion of a mixture of air and gas drives up a
light piston.
434. C. D. Abel. —Gas engine in which the explosion of air and gas, ignited
by a gas jet or electric spark, drives up a piston.
434. C. D. Abel — Regulating power of explosion.
738. M. P. W. Boulton. — Generating and applying heat for the production
of motive power and steam.
3125. R. George. — Improvements where motive power is obtained by action
on a piston traversing to and fro within a vibrating cylinder.
3363- J- Anderson. — Improvement on No. 2767/1859, the connection of
the piston with shield shell.
3448. W. Clark. — Improvements in manufacture of hydrogen gas and its
applications for lighting and heating, and as a motive power.
The Gas Engine
1867.
NO.
422. R. Shaw (provisional only). — Explosion engine details.
499. Kinder & Kinsey. — Improvements in gas engines.
571* A. V. Newton. — Improvements in gas engines.
633. A. L. Normandy. — Improvements in engines worked by heated air or
gases.
1392. William Smyth. — Motive power for actuating apparatus for navigating
the air.
1575' H. A. Bonneville. — Obtaining motive power by means of an over-
heated mixture of air and steam.
2245. C. £>. Abel. — Combined gas and air engine. The explosion of a mix-
ture of gas and air propels a light piston.
3237. W. E. Gedge (provisional only). — The burnt gases are condensed after
their action upon the driving piston in order to produce a vacuum.
3690. W. E. Newton. — Motors for generating motive power.
1868.
354. A. M. Clark. — Manufacture of gases for a gas engine.
1393. G. B. Babacci. — A vertical gas engine.
1878. J. Bourne. — Production and application of motive power. Air and
fuel, either solid, powdered, liquid, or gaseous, are blown, after being
made hot, into a hot chamber, a pump or steam jet being used.
1988. M. P. W. Boulton. — Apparatus for obtaining motive power by the
combustion of aeriform inflammable fluid.
2264. J. Gill. — Improvements in the construction of engines for motive
power.
2680. J. M. Hunter. — A vessel is provided with motive power for aerial pro-
pulsion— explosion of mixture.
2808. Bower & Hollinshead. — The construction of engines in which the
motive power is derived from the force of the explosion of air and1
gas.
3146. J. Robertson. — The generation of steam or gases to actuate motive
power engines.
3264. E. A. Rippingille. — Motive power obtained by mixing the products.
of combustion with steam.
3594. John Bourne. — Production of heat, and generation and application of
motive power.
1869.
1375. Franklin & Dubois (provisional only). — Gas engine.
1435. H. Bessemer. — Blast furnaces and blast engines, and utilising the
gaseous products from blast furnaces.
1748. A. M. Clark (provisional only) — Apparatus for producing motive
power by the use of steam or compressed gases.
Appendix II 487
NO.
3087. Hydes & Bennett. — Propelling ships by means of heated compressed
air and products of combustion combined.
3178. A. H. Brandon. — Gas or vapour engine.
3585. W. Hetherington. — Improvements in the arrangement and con-
struction of motive power engines which are actuated by heated air
or gases.
3705. J. Bourne. — Production of heat and motive power, the combustion of
solid, liquid, or gaseous fuel.
1870.
194. J. M. Plessner. — Treatment of hydrocarbons and air to produce motive
power.
440. A. H. de Villeneuve. — Machinery for generating, obtaining, and
applying motive power.
1352. E. P. H. Vaughan (provisional only). — Construction of gas engines in
which a mixture of air and combustible gas is introduced into a
cylinder between two pistons.
1859. John Bourne. — Motive power is produced from heat derived from the
combustion of solid, liquid, or gaseous fuel, and from coal reduced
to powder.
2554« William Firth (provisional only). — Improvements in steam, air, and
gas engines.
2959. E. P. H. Vaughan. — Gas engine, in which the mixture of air and
combustible gas is introduced into the cylinder between two pistons.
1871.
1724. E. N. Schmitz. — An improved gas engine.
2254. G. Haseltine. — Motive power produced by the explosive force of
gas.
2326. J. Anderson. — Producing current and developing motive power mainly
by igniting a mixture of combustible gas and air in a chamber or
channel, near an orifice, through which the gases of greatly increased
volume, due to the combustion, issue in the form of a jet.
2587. J. M. Plessner. — Obtaining motive power from the explosion of gases.
1872.
387. W. R. Lake. — Engines operated by gunpowder, gun-cotton, or other
explosive material.
821. M. A. Soul. — Navigable balloon worked by a gas engine.
1126. T. N. Palmer (provisional only) — An explosive gas engine. Any
fluid carburetted hydrogen gas or fluid, in the form of spray, is
introduced into a cylinder, where by the access of atmospheric aii
its combustion produces motive power.
488 The Gas Engine
NO.
1423. P. Jensen. — The construction of coke ovens and utilisation of the
waste heat therefrom for generating gas for gas engines and other
purposes.
1594. W. E. Newton. — Explosion engine.
2293- J« Young. — Motive power obtained from vapours given off by the
volatile hydrocarbons obtained from petroleum and paraffin oils.
3228. W. R. Lake — The warming of air (for heated air motor) effected by
means of tar, or other cheap liquid fuel, placed in a closed cylinder
and ignited.
3481. E. T. Hughes (provisional only). — The use of any liquid hydrocarbon,
such as naphtha or petroleum, which in a divided state, mixed with
atmospheric air, is injected behind a piston in a cylinder, and when
ignited, produces power by the explosion or combustion.
3641. G. Haseltine. — Utilising the vapour of hydrocarbon oils or the pro-
ducts thereof, or similar substances, for obtaining motive power.
1873-
272. W. E. Sudlow. — Rotary engines worked by hot air, gas, explosive or
otherwise, or by water pressure or steam.
329. G. Rydill. — Steam boilers and furnaces, heating air and gases, and
producing motive power from a mixture of steam and products
of combustion for working a steam engine, and for other purposes.
1628. J. Imray (provisional only). — Method of and apparatus for obtaining
motive power from heated air, gas, or gaseous products of combus-
tion admitted to a cylinder at the pressure of the atmosphere.
1946. J. Imray. — Obtaining motive -power from heated air, gas, or gaseous
products of combustion admitted to a cylinder at the pressure of the
atmosphere and cooled therein, so that their pressure on one side
of the piston being reduced below that of the atmosphere, the ex-
cess of atmospheric pressure on the other side of the piston shall
effect its propulsion.
3848. W. R. Lake.— Gas engines driven by the explosion of combustible
gas or vapour mixed with air.
4088. F. W. Turner. — Gas engines, in which a wheel, arranged with a pro-
jecting rim having bevelled grooves on the inside, is keyed on the
main shaft.
1874.
25. R. Gottheil. — An explosive gas engine, having a cylinder open at one
end, and provided with two pistons, one of which may be termed
the working piston, and is connected in the usual way to a crank on
the main shaft, while the other, which may be called the loose piston,
has a rod passing through the cylinder cover, and through the two
friction cheeks mounted on levers, so as to admit of free movement
Appendix II 489
NO.
of the piston rod in one direction, while its movement in the other
direction is checked, owing to the cheeks embracing the rod tightly.
414. C. D. Abel. — Gas engine, in which a slide is arranged to operate upon
a single passage for inlet to and outlet from the cylinder ; this
engine is regulated by a governor, so as to economise the expendi-
ture of gas.
486. S. Ford. — A rotary gas engine worked by the explosive force of gas.
493. J. Hock. — Engines worked by the combustion of petroleum, naphtha,
or other liquid hydrocarbons, such combustion producing pressure
in a cylinder to work a piston connected to a crank on a fly-wheel
shaft.
509. R. M. Marchant. — Combined air, steam and caloric engine.
605. C. D. Abel. — Improvements in gas motor engines.
777. J. D. Ridley. — Aerial machine, in which a piston actuates the wings of
the apparatus, causing it to reciprocate in a cylinder by alternate
explosions of gunpowder, or other explosive agent, fired by elec-
tricity.
961. C. Carobbi & G. Bellini.— Locomotive and other engines, worked
by air compressed by the combustion of fulminating matters, such
as cotton, hemp, linen, tow, or similar substances, formed into a
rope, and treated with a mixture of concentrated azotic and sul-
phuric acid.
1652. E. Butterworth (provisional only). — Preventing the over-heating of a
cylinder, exhaust valve, and adjacent pipes.
2209. G. Ilaseltine. — Improvements in gas engines.
2441. F. Jenkin. — Thermo-dynamic engine, or ' fuel engine,' the primitive
type of which is Stirling's air engine.
2795. J- H- Johnson. — Generating and applying the motive power of gases.
3189. R. M. Marchant (provisional only). — Combined air, steam, and caloric
engines. Gas used as fuel.
3190. R. M. Marchant (provisional only). — Steam and other motive power
engines, and manufacture of gas.
3205. F. W. Crossley. — Improvements in gas motor engines.
3257. C. T. E. LasceHes. — Gas engines for propelling tramway cars and
other vehicles.
.4410. Kirkwood, Lascelles, & Hall (provisional only). — Gas engines used
as motors for tramway cars and other vehicles.
1875-
71. C. D. Abel. — Motor engines worked by gas or combustible vapour and
air.
175. P. Vera. — Gas and hot air engines.
265. E. C. Mills and H. Haley. — Explosive gas engines.
744. J. F. Dickson. — Improvements in air and gas engines.
49° The Gas Engine
NO.
2016. De V. Bruce & T. M. Antisell.— Utilising the expansive force of
vapours or gases, either by gradual pressure or explosion, in
engines.
2334- W. W. Smyth & G. G. Hunt. —Gas engine with two single-acting
cylinders.
2826. R. Hallewell. — Explosive gas engines.
3221. F. W. & W. J. Crossley. — Improvements in gas motor engine.
3274. Q. L. Brin. — Obtaining motive power by the explosion of gas and air
acting directly or indirectly on water or oil.
3615. C. D. Abel. — Improvements in gas and air engines.
4326. J. H. T. Ellerbeck & J. M. Syers. — Explosive gas motor (provisional
only).
4342. E. P. Alexander.— Gas motive power engines, and means of regulating
and transmitting their motion for driving, sewing, electric, and other
machines, and fans or pumps.
1876.
88. Thacker (provisional only). — Improvements in gas engines.
132. Crossley. — Improvements in gas motor engines.
1034. Kidd (provisional only). — Improvements in gas-producing furnaces
and in the methods of utilising the gases generated therefrom.
1520. Wirth (Humboldt Manufacturing Co.). — Improvements in gas engines.
1961. Lascelles. — Improvements in gas and other explosive motive power
engines.
2081. Abel (Otto). — Improvements in gas motor engines.
2288. Boulton. — Improvements in apparatus whereby combustion under
pressure is applied to generate fluid for working engines.
2824. Lin ford. — Improvements in gas engines and in appliances connected
thereto.
3-191. De Kierzkowski. --Improvements in pressure generators for motive
engines, and in the application of motive engines to the propulsion of
tram cars, £c.
3370. Redfern (Sack& Reunert). — Improvements in gas motor engines and
in apparatus connected therewith.
3435. Simon (provisional only). — Improvements in the construction of
engines to be worked by power derived from air and oil com-
bined.
3444. Johnson (Wertheim). — Improvements in obtaining and applying
motive power, and in the apparatus employed therein.
3620. Boulton. — Improvements in engines worked by the combustion and
expansive force of an inflammable fluid mixture.
3767. Boulton. — Improvements in apparatus for the production of motive
power jointly by the elastic force of products of combustion, and of
steam or vapour.
Appendix II 49 r
NO.
4987. Hallevvell. — Improvements in gas motor engines.
4988. Hallewell. — Improvements in gas and water motor engines.
1877.
252. Clerk. — Improvements in motive power engines working with hydro-
carbon gas or vapour.
491. Otto £ Crossley. — Improvements in gas motor engines.
711. Roberts (provisional only).— Improved machinery or apparatus for
propelling tramway cars and other like vehicles.
766. Boulton. — Improvements in engines worked by products of combustion
either alone or in conjunction with other elastic fluid.
819. Hallewell. — Improvements in gas motor engines and in the valve of
such engines.
Lake (Wertheim). — Improvements in gas motor engines.
Linford. — Improvements connected with gas engines.
Crossley (F. W. & W. J.).— Improvements in gas motor engines.
Robson. — Improvements in engines operated by the combustion of gas
or vapour.
Simon & Muller (provisional only). — Improvements in gas engines.
Simon. — Improvements connected with atmospheric gas engines.
Mills & Haley. — Improvements in motive power engines worked by
the explosion of gas.
3121. Wilson and others (provisional only). — Improvements in engines, and
apparatus for the propulsion of vehicles on roads and rails.
3122. Wilson and others (provisional only). — Improvements in gas motors.
3I59- Johnson (La Societe des Moteurs Lambrigot). — Improvements in
effecting the conversion of hydrocarbons, &c., into gas, and in
apparatus or means employed therein, and in or for the production
and application of gaseous mixtures.
4052. Weyhe. — Improvements in gas motor engines.
4937. Simon (Kindermann) (provisional only). — Improvements in gas motor
engines.
1878.
10. Hilton & J. & S. Johnson (provisional only). —Improvements in the ap-
plication of gas motors to tram cars and other self-propelling vehicles.
228. Ramsbottom. — Improvements in engines for obtaining motive power
from liquid and gaseous fluids, and for pumping and compressing.
290. Pieper (Schaeffer) (provisional only).— An improved gas motor.
433. Simon (L. & R.). — Improvements in and connected with gas engines.
942. Linford. — Improvements in gas engines.
1170. Baron. — Improvements in motive power engines.
1770. Abel (Otto) (provisional only).— Improvements in apparatus for
igniting the charges of gas motor engines.
492 The Gas Engine
NO.
1798. Hallewell. — Improvements in gas engines, applicable in part to
other uses.
1997. liannoversche Maschinenbau-Actien-Gesellschaft, The. — Improve-
ments in gas engines with two pistons.
2037. Clayton. — Improvements in gas motor engines and in apparatus con-
nected therewith.
2278. Boulton (provisional only) — Improvements in gas motor engines.
2474. Johnson (Fra^ois). — Improvements in obtaining motive power and
in the machinery or apparatus employed therein.
2525. Boulton (provisional only). — Improvements in gas motor engines.
.2609. Boulton (provisional only). — Improvements in gas motor engines.
2707. Boulton. — Improvements in combined gas and steam motor engines.
2901. Waller. — Improvements in gas, steam, air, and other motive power
engines and in apparatus in connection therewith.
3045. Clerk. — Improvements in gas motor engines.
3056. Leichsenring. — Improvements in and relating to engines worked by gas
or other fluid, partly applicable to apparatus for compressing fluids.
3444. Cropper & Johnson. — Improvements in valves for gas engines.
3774. Casson (provisional only). — Improved means and apparatus for work-
ing clocks and bells (by combustion of gas).
3972. Weatherhogg. — Improvements in gas motor engines.
4630. Foulis (provisional only). — Improvements in motive power engines.
4760. Duncan & W. G. Wilson (provisional only). — Improvements in gas
motors.
4782. Lake (Lay) (provisional only). — Improvements in apparatus for pro-
pelling, guiding, &c., torpedo boats.
4843. Foulis. — Improvements in gas and hydrocarbon engines, and in ignit-
ing the gas or hydrocarbon, applicable for other purposes.
4979. Simon and another. — Improvements in and connected with gas or
hydrocarbon engines.
4987. Lake (Lay). — Improvements in apparatus for propelling, guiding &c.
torpedo boats.
5092. Hallewell. — Improvements in gas motor engines.
5113. Crossley and another. — Improvements in gas motor engines.
l879.
2. Williams & Baron. — Improvements in and relating to atmospheric
air and gas motor engines.
309. Pieper (Krauss). — A gas power locomotive for tramways and for rail-
ways of secondary order.
392. Shaw (provisional only). — Improvements in gas motor engines.
495. Boulton. — Improvements in caloric engines.
Appendix II 493
NO.
540. Donald (provisional only). — Improvements in and connected with gas
engines.
750. Simon (Todt) (provisional only). — Improvements in vapour or gas
motor engines.
1161. Graddon. — Improvements in machinery or apparatus for generating.
motive power &c. &c.
1270. Turner. — Improvements in and relating to gas motor engines.
1450. Hallewell. — Improvements in compound gas engines.
1500. Linford. — Improvements in gas engines.
1727. Purssell (provisional only). — Improvements in gas engines to adapt
them for locomotive purposes.
1912. Holt & Crossley (provisional only). — Improvements in machinery for
starting, propelling, and stopping vehicles, and in the apparatus and
appliances connected therewith, more particularly with reference to
gas engines &c. &c.
I933- Sombart (Buss). — Improvements in gas engines.
1947. Newton & Cowper (provisional only). — Improvements in prime
movers and apparatus actuated by fluid pressure, applicable wholly
or in part to pumps and other apparatus.
1996. Clark (Fell).— Improvements in the production of motive power and
in apparatus for the same.
2073. Foulis. — Improvements in that class of motive power engines known
as gas or hydrocarbon engines.
2152. Woolfe. — Improvements in the construction of gas motor engines.
2191. Benson (Rider). — Improvements in gas engines.
2193. Kurd. — A condensing or non-condensing compound single or double
acting motive power engine, worked by explosive gases, collected
from mines or otherwise, in combination with or without gun-cotton,.
or with gun-cotton alone, £c.
2424. Clerk. — Improvements in gas motor engines.
2618. Butcher (provisional only). — Improvements in gas motor engines.
2732. Johnson (provisional only). — Improvements in gas engines.
3140. Clayton. — Improvements in motor engines worked by gas or com-
bustible vapour and air.
3213. Atkinson. — Improvements in gas and similar engines and mechanism
connected therewith, partly applicable to other purposes.
3233. Simon. — Improvements in gas engines worked by the combustion or
explosion of a compressed mixture of gas and air or hydrocarbon
and air.
3245. Abel (Daimler). — Improvements in gas motor engines.
3467. Dalton & Ken worthy. — Improvements in propelling carriages and in
the apparatus employed therein.
3561. Picking & Hopkins. — Improvements in gas motor engines.
3732. Glaser (Wittig& Hees). — Improvements in gas and petroleum engines.
494 The Gas Engine
NO.
3905. Alexander (Angele) (provisional only). — Improvements in gas motors.
4101. Emmet & Cousins. — Improvements in gas engines.
4337- King. — Improvements in and connected with engines actuated by the
explosion or combustion of a mixture of gas and air.
4340. Williams. — Improvements in and relating to atmospheric air and gas
motor engines.
4377. Butcher. — Improvements in gas motor engines.
4396. Purssell. — An improved arrangement of apparatus for moving tram
cars &c. by gas engine power.
4483. Graddon (provisional only). — An improved motive power engine
actuated by an explosive fluid or gas, part of which may be applied
to other gas engines.
4485. Wigham (provisional only). — Improvements in gas motor engines.
4492. Shaw (provisional only).— Improvements in gas motor engines.
4499. Holt & Crossley. — Improvements in machinery &c. for stopping &c.
the direction of motion of vehicles on rails, &c. , more particularly
applicable to gas engines, but also suitable for other motor engines.
4501. Robson. — Improvements in gas engines.
4755. Foulis. — Improvements in gas engines.
4820. Edmonds (Francois). — A new or improved gas motor or engine and
new arrangements of mechanism employed with the same.
5052. Mills & Haley. — Improvements in gas motor engines.
1880.
9. Pottle. — Improvements in governors for steam engines and other
motors.
117. Robinson. — Improvements in gas motor engines.
330. Linford. — Improvements in and connected with gas engines.
343. Abel (Daimler). — Improvements in gas motor engines.
473. Newton. — Improvements in crossheads for motive power engines.
474. Butcher. — Improvements in tramway, locomotive, and other engines,
and in apparatus connected therewith.
533. Thompson (Geisenberger). — Improvements in and appertaining to
gas engines, or engines actuated by the explosion or combustion of
mixed gas or vapour and air.
760. Edwards. — Improvements in motive power engines actuated by the
combustion of a mixture of gas and air, or by the pressure of steam
or other elastic fluid, parts of which invention are also applicable
to other purposes.
1131. Johnson (provisional only). — Improvements in gas engines.
1653. Beechey (provisional only). — Improvements in engines worked by
gas and air or other hydrocarbons.
1692. Williams & Malam. — Improvements in and relating to atmospberic
air and gas motor engines.
Appendix II 495
NO.
1736. Sombart (provisional only). — Improvements in gas engines.
1969. Haigh & Nuttall. — Improvements in gas engines.
2181. Wordsworth (provisional only). — Improvements in gas motor engines.
2182. Lake (.Lay). — Improvements in apparatus for facilitating the control
and operation of torpedo boats.
2290. Hardaker. — Improvements in road vehicles or velocipedes.
2299. Livesey (Livesey). — Improvements in gas motor engines.
2344. Robinson. — Improvements in gas motor engines.
2422. Foulis. — Improvements in gas engines.
3140. Lake (Breittmayer). — Improvements in gas engines.
3176. Northcott. — Improvements in engines and apparatus for producing
motive power (relating to gaseous fuel engines).
3182. Turner. — Improvement in gas motor engines.
3411. Holt & Crossley. — Improvement in locomotives for tramways and
light railways.
3512. Aylesbury. — Improvements in gas engines or motors.
3607. Jenner. — Improvements in gas engines.
3652. Wilson. — Improvements in vertical steam and other motive power
engines.
3685. Williams & Malam. — Improvements in and relating to atmospheric
air and gas motor engines.
3869. Purssell. — Improvements in the construction, arrangement, and
method of action of gas engines.
3913. Lawson (provisional only). — Improvements in velocipedes and in the
application of motive power thereto, applicable to other, &c.
4050. Robson. — Improvements in obtaining and applying motive power.
4075. * Clayton. — Improvements in motor engines worked by gas or combus-
tible vapour and air.
41 59. Kesseler (Henniges) (provisional only). — Improvements in the Simon's
steam gas motor with burning flame in the cylinder.
4201. Jensen (provisional only). — Improvements in burners for producing
and burning petroleum gas.
4260. Robinson. — Improvements in gas motor engines.
4270. Beechey. — Improvements in gas motor engines.
4297. Crossley. — Improvements in gas motor engines.
4398. Rhodes and others. — Improvements in gas motor engines.
4419. Benson (Rider). — Improvements in gas engines.
4547. MacFarlane (provisional only). — A new or improved gas engine.
4633. Bickerton (provisional only). — Improvements in gas motor engines.
4819. Muller. — Improvements in or additions to gas engines.
4881. Simon & Wertenbruch. — Improvements in gas motor engines.
5024. Home (provisional only). — Improvements in gas engines.
5090. Foulis (provisional only). — Improvements in gas engines.
5101. Richardson (provisional only). — Improvements in gas engines and in
apparatus connected therewith for the supply of gas to them.
496 The Gas Engine
NO.
5130. Livesey (Livesey). — Improvements in compound gas motor engines.
5219. Fiddes. — Improvements in gas motor engines.
5269. Wigham (provisional only). — Improvements in locomotive engines for
tramways, &c.
5347. Robinson. — Improvements in engines to be worked by steam, air, or
gas.
5471. Hutchinson. — Improvements in gas motor engines.
5479. Graddon. — Improvements in machinery or apparatus for obtaining and
applying motive power, partly applicable to other purposes.
1881.
60. Abel (Otto). — Improvements in gas motor engines.
125. Haddan (Nix & Helbig) (provisional only). — Improvements in gas
engines.
1 80. Foulis. — Improvements in gas engines.
320. Sombart. — Improvements in gas engines.
370. Holt & Crossley. — Improvements in connection with gas motor
engines, and locomotives worked thereby.
532. Fielding. — Improvements in gas motor engines.
565. Allcock. — Improvements in gas engines.
798. Ord (provisional only). — Improvements in gas engines.
799. Graddon (provisional only). — An improved construction of gas engines.
8li. Haigh & Nuttall. — Improvements in the construction of gas engines.
867. Wenham. — Improvements in combined gas and heated air engines.
1074. Bauer & Lamart. — Improvements in gas engines.
1089. Clerk. — Improvements in motors worked by combustible gas or
vapour.
1 202. Boulton (provisional only). — Improvements in caloric engines wherein
the working fluid is heated by internal combustion of gas.
1363. Bickerton. — Improvements in gas motor engines.
1382. Groth (Schoufeldt and another) (provisional only). — A new or im-
proved reversible rotary engine.
1388. Ewins £ Newman, — Certain improvements in gas engines.
1389. Boulton. — Improvements in caloric engines wherein the working fluid
is heated by internal combustion of gas.
1409. G wynne & Ellis. — Improvements in gas motor engines.
1541. Benier (provisional only). — Improvements in gas engines.
1 723. Watson. — An improved method of exploding gases used in gas engines.
1763. Watson (provisional only). — Improvements in gas engines.
1765. Edwards. — Improvements in motive power engines actuated by the
combustion of a mixture of gas and air.
2083. Robson. — Improvements in motive power engines.
2122. Dougill. — Improvements in gas motor engines, in the method of regu-
lating the speed thereof, and of admitting combustible material into
the cylinder and allowing the escape of exhausted products, &c.
Appendix II 497
Crossley. — Improvements in the method and apparatus for supplying
gas to movable gas motor engines.
Ford. — Improvements in gas engines.
Siemens. — Improvements in gas motors and producers.
Wigham.— Improvements in locomotive engines for tramways, rail-
ways, &c.
Pinkney. — Improvements in gas engines.
Mills.— Improvements in obtaining motive power.
Levassor. — An improved motive power engine.
Watson. — An improved means or method of exploding gases in gas
engines. .
De Pass (Kortung). — Improvements in gas engines.
Beechey. — Improvements in gas motor engines.
Wastfield (provisional only). — Improvements in gas engines.
Linford & Linford. — Improvements in and connected with gas engines.
Eteve & Lallement. — A new or improved motive power engine
operated by hydrocarburetted air.
3275. Ord. — Improvements in gas motor engines.
3330. Brydges (Schiltz). — Improvements in gas, hydrocarbon, and other
motive power engines.
3367. Boulton. — Improvements in engines wherein a piston is propelled in a
cylinder by ignition of inflammable gas or fluid.
3415. Justice (Osam). — Improvements in the utilisation of the gaseous pro-
ducts of combustion, and in apparatus therefor (provisional only).
3450. Crossley & Holt (provisional only). — An improved governor for gas
motor engines.
3527. Lucas. — Improvements in gas engines.
3536. Stern, Clerk, & Handyside. — Improvements in refrigerating machines,
and in part applicable to gas motors, &c.
3561. Kirkhove £ Snyers. — A new or improved method and machinery for
direct propulsion of land, water, and aerial motors or engines, appli-
cable also to stationary engines.
Williams. — Improvements in gas engines and the automatic generation
of gas therefor.
Butcher.— Improvements in gas motor engines, and in arrangements
for starting and re-starting the same.
Atkinson. — Improvements in gas engines.
Watson. — Improvements in obtaining motive power by means of com-
bustible gas or vapour, and in apparatus therefor.
King. — Improvements in gas motor engines.
Abel (Spiel). — Improvement in motor ^ngines worked by combustible
gases or vapours and steam.
Simon & Wertenbruch. — Improvements in the construction and
method of action in gas engines.
Wordsworth and others. — Improvements in gas motor engines.
K K
49 8 The Gas Engine
NO
4402. Weatherhogg. — Improvements in single and double acting compound
air and gas motor engines.
4407. Drake & Muirhead (provisional only). — Improvements in and con-
nected with gas engines.
4493. Royle. — Improvements in and apparatus for lubricating steam and
gas engines, and for other lubricating purposes, &c.
4589. Be'nier & Lamart (provisional only). — Improvements in gas engines.
4608. Watson. — Improvements in gas engines.
4830. Lake (Lay). — Improvements in and relating to boats to be propelled
by gas, &c.
5178. Shaw. — Improvements in gas motor engines.
5201. Tonkin Improvements in motive power engines actuated by the
combustion or explosion of mixtures of gas or combustible vapour
with air, &c. ; applicable to other purposes.
5259. Rhodes (provisional only). — Improvements in and appertaining to gas
engines or engines actuated by the explosion or combustion of mixed
gas or vapour and air.
5350. Siemens. — Improvements in engines worked by the combustion of
gaseous fuel.
5456. Williams. — Improvements in and relating to atmospheric air and gas
motor engines.
5469. Crossley & Holt. — Improvements in gas motor engines, part of which
improvements are applicable to steam engines, &c.
5483. Griffin. — Improvements in gas motor engines.
5534. Beck (Montelar). — A gas locomotor for the locomotion of carriages, &c.
(provisional only).
5575. Quick and another. — Improvements in tramway locomotives and other
locomotives or motive power engines.
1882.
362. Turner. — Improvements in gas engines.
397. Emmet. — Improvements in gas engines.
417. Withers. — Improvements in gas engines.
579. Johnson (Bisschop). — Improvements in gas engines.
614. Haigh & Nuttall. — Improvements in the construction of gas engines.
659. Wastfield (provisional only) Improvements in gas engines.
678. Watson (provisional only). — Improvements in gas engines.
703. Wordsworth & Lindley. — Improvements in gas engines.
994. Fielding — Improvements in and connected with gas motor engines.
1026. Niel.— Improvements in gas engines.
1318. Beechey. — Improvements in gas motor engines.
1360. Sumner. — Improvements in gas motor engines.
1590. Skene. — Improvements in gas motor engines.
1717. Drake & Muirhead. — Improvements in and connected with gas engines.
Appendix II 499
NO.
1754. Anderson & Crossley. — Improvements in the ignition apparatus
motor engines.
1868. Dufrene, Benier, & Lamart. — Improvements in gas engines.
1874. Brown. — Improved means of, and apparatus for, the production of gas
by the combustion of carbon compounds, &c.
1910. Skinner (provisional only) — Improvements in engines which are driven
by means of the explosive force of gases.
.2008. Glaser (Teichmann) (provisional only). — Improvements in caloric and
gas power engines. .
2057. Sombart. — Improvements in gas engines.
2058. Porteous. — Improvements in gas engines.
2126. Worssam. — Improvements in gas motor engines.
2202. Clayton. — Improvements in motor engines worked by gas or combus-
tible vapour and air.
2231. Russ (provisional only). — Improvements in the manufacture of gas for
lighting, heating, &c., and for utilising the same for motive power.
2257. Nobbs. — Improvements in gas engines.
2329. Hutchinson. — Improvements in gas engines.
.2337. Guthrie (provisional only). — Improvements in and relating to engines
and apparatus connected therewith for developing the expansive force
of air or gas and utilising the same for motive power.
3342. Watson (provisional only). — Improvements in gas engines.
12345. Bickerton and another. — Improvements in and applicable togas motor
engines.
2423. Thompson (Marcus). — Improvements in or appertaining to motors
actuated by the explosion of comminuted liquids, &c.
2527. Davey. — Improvements in apparatus for the production of inflammable
gas and applying its combustion for the production of motive power.
2751. Braham & Sealon (provisional only). — Improvements in gas engines.
'2753- Wordsworth & Wolstenholme. — Improvements in gas motor engines.
3375. Robinson. — Improvements in and apparatus for obtaining motive power
for propelling vessels, pumping fluids, and other analogous purposes.
3435. Abel (Beissel). — Improvements in gas motor engines.
3449. Holt & Crossley (provisional only). — Improvements in gas motor
engines.
3540. Hargreaves. — Improvements in thermo-dynamic engines.
3787. Davey. — Improvements in apparatus for generating elastic fluid under
pressure ; available for working engines.
3819. McGillivray. — Improvements in gas engines.
.4363. Clark (Schweizer). — Improvements in gas engines.
4378. Atkinson. — Improvements in gas engines.
4388. Atkinson. — Improvements in gas engines.
4418. Watts & Smith. — Improvements in and connected with motors worked
by combustible gas, vapour, steam, &c.
4489. Crossley. — Improvements in gas motor engines.
K K 2
5oo The Gas Engine
NO.
4755- Wastfield. — Improvements in and relating to gas engines.
4773. Wastfield (provisional only). — Improvements in and relating to gas
engines.
4886. Baldwin (provisional only). — Improvements in gas engines and in
apparatus connected therewith.
4948. Clerk.— Improvements in motive power engines worked by combus-
tible gas or vapour.
5042. Gedge (Marti & Quaglio). — Improvements in rotary gas engines.
5188. Ashbury and others. — Improvements in gas motor engines.
5371. Russ (provisional only). — Improved arrangement of machinery for the
manufacture of gas for lighting, heating, and motive power purposes.
5506. Mewburn (Goubet). — An improved rotary gas or explosion engine.
5510. Maynes. — Improvements in gas motor engines.
5527. Dyson (provisional only). — Improvements in or applicable to gas-
engines employed in connection with tramcars, &c.
5782. Watson. — Improvements in gas engines.
5819. Whittaker. — Improvements in or applicable to gas motor engines.
5825. Odling (provisional only). — Improvements in gas motor engines.
5865. Butcher (provisional only). — Improvement in gas motor engines.
6130. Clark (Laureni). — Improvements in gas engines.
6136. Bennet & Walker. — Improvements in motive power engines, which
improvements are also applicable to gas engines.
6214. Watson. — Improvements in gas engines.
1883.
19. Forest. — An improved construction of gas motor engine.
21. Woodhead. — Improvements in gas motor engines.
130. Odling. — Improvements in gas motor engines.
132. Lake (Maxim) (provisional only). — Improvements in gas engines.
300. Williams. — An improvement in engines for motive power, compression,
and other like purposes.
326. Linford & Cooke. — Improvements in gas engines.
388. Howard & Bousfield (provisional only). — Improvements in gas
engines.
499. Weatherhogg. — Improvements in air and gas motors and apparatus for
the production of gas therefor.
638. King & Cliff. — Improvements in gas motor engines.
781. Townsend & Davies. — Improvements in gas motor engines.
836. Imray (Schweizer) — An improvement in gas motor engines,
911. Capell. — Improvements in motors worked by air, gas, &c., or explosive
mixtures, &c.
999. Clark (Kabath) — Improvements in gas and other engines.
1010. Andrew Improvements in gas engines.
1019. Handford (Edison). — Improvements relating to the operation of
electrical generators by gas engines.
Appendix II 501
NO.
1060. Martini. — A new gas motor.
1098. Wastfield. — Improvements in and applicable to gas engines.
1116. Steel & Whitehead. — Improvements in gas engines.
1501. Marchant & Wrigley — Improvements in the application and storage
of illuminating or other like gas to motors for driving tramcars or
other vehicles, and for the purpose of starting and working gas
engines, and in means employed.
1677. Abel (Otto). — Improvements in gas motor engines.
1722. Crossley (provisional onrly) An improvement in gas motor engine
slide apparatus.
1835. Butcher. — Improvements in gas motor engines and in applying them
to pumping purposes.
2192. Justice (Hale) — Improvements in and connected with gas engine,
and in the method and means for regulating explosive charge.
2492. Picking & Hopkins. — Improvements in gas motor engines.
2517. Haigh & Nuttall. — Improvements in gas engines.
2561. Nash Improvements in the means for operating gas engines.
2702. Pieper (Korting & Lieckfeld) — Improvements in gas motors.
2706. Crowe and others. — Improvements in gas caloric motive engines.
2790. Thompson (Marcus) — Improvements in gas motor engines.
2927. Whitehead A new or improved gas motor engine.
3041. Russom (provisional only). — Improvements in gas engines.
3066. Andrew. — Improvements in gas motor engines.
3069. Williams. — Improved means of, and apparatus for, converting recipro-
catory into rotary motion in gas and other explosive engines, and in
hydraulic, steam, air, or other fluid motors ; also for effecting and
governing explosions in gas and other such engines, parts of which
are also applicable as air and other fluid compressors.
3070. Fielding Improvements in gas motor engines, in part applicable to
other engines.
3079. Crossley — Improvements in gas motor engines.
3097. Dougill. — Improvements in gas motor engines.
3135. Niel — Improvements in the construction and arrangement of gas
engines.
3272. Kirchenpauer & Philippi. — Improvements in gas motor engines.
3280. Foulis. — Improvements in gas engines.
3336. Holder — Improvements in gas motors.
3383. Lake (Gardie). — Improvements in and relating to gas engines.
3568. Wordsworth & Lindley. — Improvements in gas motor engines.
3703. Pickering — Improvements in gas engines.
4008. Button (Spiel). —Improvements in gas or inflammable liquid engines
or prime movers.
4023. Quack (provisional only) — Improvements in gas engines.
4046. Clerk, — Improvements in gas motors.
5O2 The Gas Engine
NO.
4080. Griffin. — Improvements in the arrangement and construction of gas
motor engines.
4193. Racholz (provisional only) — Improvements in oil-gas engines, whereby
the said engine produces its own gas from oil waste.
4242. Ladd (Serrell). — Improvements in and relating to gas engines.
4260. Clark (Economic Motor Company). — Improvements in gas engines.
4291. Andrew — Improvements in gas engines.
4455. Haddan (Schiltz.) — Improvements in gas and petroleum engines.
4816. Williamson and others Improvements in gas motor engines.
5020. Briscall and another (provisional only) — Improvements in and relating
to gas motor engines.
5042. Lake (Kabath) — Improvements in electrical igniting apparatus for gas
engines.
5085. Bullock. — Improvements in gas motor engines.
5113. Bull — Improvements in gas engines.
5265. Justice (Hale) — Improvements in and connected with gas engines,
and in the means and method of supplying explosive charges thereto.
5297. Wirth (Sohnlein) (provisional only).— Improvements in petroleum
motors.
5315. Johnson (Lenoir) — Improvements in gas engines.
5331. Robson (provisional only).— Improvements in gas engines.
5406. Picking & Hopkins — Improvements in gas motor engines.
5543. Nash — Improvements in the construction of gas engires, and in certain
methods of operating the same.
5570. Williamson and others (provisional only). — Improvements in gas motor
engines.
5632. Nash — Improvements in the construction of gas engines.
5633. Nash — Improvements in the construction of gas engines.
5721. Mills — Improvements in gas motor engines.
5784. Groth (Daimler) Improvements in gas or oil motors.
5923. Sombart.— Improvements in gas engines.
5928. Welch & Rapier — Improvements in gas engines.
5951. Campbell (provisional only).— Improvements in gas motor engine.
5956. Wastfield — Improvements in and relating to gas engines.
5976. Tonkin — Improvements in motive power engines actuated by the
combustion or explosion of mixtures of gas or combustible vapours.
with air, parts of which improvements are applicable to other engines.
1884.
325, Hargreaves. — Increasing efficiency of thermodynamic engines.
454. Skene — Improvements in gas engines.
560. Steel & Whitehead. — Improvements in gas engines.
I373- Sterne. — Exhaust silencer.
Appendix II 503
NO.
1457. Wirth (Bernstein). — Improvements in apparatus for, and the method
of, producing motive power by the explosion of coal or carbon dust
and air.
2088. Rodgerson -Improvements in gas motor engines.
2135. Henderson (Eteve & Braam) — An improved petroleum or hydro-
carbon engine.
2289. Rockhill. — Improvements in or relating to brakes for gas or other
engines.
2715. Woodhead — Improvements in gas motor engines.
2854. Clayton. — Improvements in gas motor engines.
2933. Fielding. — Improvements in gas motor engines.
3039. Atkinson Improvements in gas engines.
3495. Cobham & Gillespie — Improvements in gas engines.
3537. Holt & Crossley. — An improved apparatus for starting gas motor engines.
3758. Griffin Improvements in piston-rod stuffing-boxes for gas motor
engines.
3893. Holt. — Compressing pumps for gas motor engines.
3986. Johnson (Deboutteville & Malandin) — Improvements in gas engines.
4391. Williamson £ others. — Improvements in gas motor engines.
4591. Munden — Improvements in gas motor engines.
4639. Pollock. — Improvements in valves for gas engines.
4736. Wirth (Sohnlein) — Improvements in gas engines.
4776. Spence. — Improvements in gas engines.
4777- Crossley — Gas motor engines.
4880. Weatherhogg. — Improvements in gas motor engines.
5007. Hill & Hill — Improvements in engines worked by gas or vapour.
5302. Johns £ Johns. — Improvements in rotary gas engines.
53°3- Johns & Johns — Improvements in rotary gas engines and other rotary
motors.
5412. Dewhurst. — Improvements in and connected with gas engines.
5435. Park — Improvements in rotary engines and pumps.
5641. Butcher — Improved igniting valve for gas engines.
5797. Lin ford & Piercy — Improvements in gas engines.
6597. Shann. — Improvements in the machinery for obtaining rotary motion
by the action of two forces on different cranks.
6652. Johnson.— Improvements in apparatus for carburetting air.
6662. Wiegand.— Improvements in gas engines.
6784. McNeill Improvements in tramway locomotives driven by gas.
7284. King — Improvements in gas motor engines.
7288. King. — Improvements in gas motor engines.
8211. Holt.— Compound gas motor engine.
8232. Sombart Improvements in gas engines.
8489. Green — Improvements in gas motor engines, and in the means or
method of supplying them with gas.
504 The Gas Engine
NO.
8565. Rogers. — Improvements in gas engines.
8579. Shaw. — Improvements in gas motor engines.
8637. Crossley. — Improvements in Otto and other gas engines.
8960. Ainsworth. — Improvements in gas engine cylinders.
9001. Guthrie Improvements in gas engines.
9112. Groth (Daimler). — Improvements in gas or oil motors.
9167. Williamson and others — Improvements in or relating to valves for gas
motor engines.
9544. Magee.— Improvements in gas engines.
9645. Welch & Rapier. — Improvements in gas engines.
9949. Capitaine (Benz & Co.) Improvements in gas motors.
10062. Norrington — Improvements in means for assisting velocipedes and gas
engines to start.
10364. Wallace. —Improved apparatus for converting reciprocating recti-
linear motion into rotary motion.
10483. Guthrie — Improvements in caloric engines.
11086. Butterworth Improvements in motors worked by combustible gas
or vapour.
11361. Justice (Backeljau) — Improvements in and connected with automatic
gas motors.
11576. Griffin Improvements in apparatus for lubricating gas and other
motor engines and machines.
11578. Crossley — Improvements in gas motor engines.
11750. Douglas. —Improvements in gas engines.
11837. Clark (Hopkins) — Improvements in gas engines.
1 220 1. Griffith Improvements in and connected with gas engines.
12264. Davy. — Improvements in gas engines.
12312. Brine — Improvements in gas engines.
12318. Dougill — Improvements in gas motor engines.
12431. Purnell An improvement in gas motor engines.
12603. Hill & Hill — Improvements in engines worked by gas or
vapour.
12640. Tellier. — Motive power by gas, steam, combustible fluids, &c.
12714. Reddie (Murray) — Improvements in gas engines.
12776. Wilson — Improvements in the construction of tramway engines
driven by gas.
13221. Andrew — Improvements in gas motor engines.
13283. Redfern (McDonough).— Improvements in gas engines.
J3573- Fairfax — Improvements in rotary and reciprocating engines.
13776. Parker — Improvements in gas motor engines.
13935. Lawson. — Improvements in gas engines for pumping water and for
other uses.
14311. Griffin — Improvements in gas motor engines.
14341. Browett — Improvements in gas motor engines.
Appendix II 505
KO.
14512. Prentice & Prentice. — Apparatus for igniting gas engine charges at
starting.
14765. McGillivray Improvements in gas engines.
15248. Johnson (Deboutteville & Malandin). — Improvements in carburetters.
15311. Holt & Crossley Compound gas motor engine.
15312. Holt. — Gas motor engine.
15633. Newton Improvements in gas motor engines.
16131. Benier Improvements in hot air engines.
16404. Atkinson Improvements in gas engines.
16634. Muller and others — Improvements in gas engines.
16698. Turner. — Improvements in gas motor engines.
16890. Regan. — Improvements in or connected with electric igniting appa-
ratus for gas engines.
16947. Imray (Barnes & Banks).— Gas motor for tramcar.
1885.
610. Johnson (Lenoir) — Improvements in or connected with gas engines.
848. Myers. — Improvements in gas motor engines.
1218. Pinkney. — Improvements in governors for gas engines, steam engines,
and compressed-air engines.
1363. Simon — An improved construction and arrangement of gas engine.
1424. Asher & Buttress.— A new or improved method of obtaining motive
power by the explosive combination of substances.
1478. Williamson, King & Ireland Improvements in ignition apparatus
for gas motors.
1581. Kempster, jun — An improved motor driven by the explosion of
hydrocarbon vapour.
1700. King — Improvements in gas motor engines.
1703. Wright & Charlton — Improvements in heat motors, such improve-
ments relating to petroleum and other hydrocarbon explosive
engines.
2712. Atkinson — Improvements in gas engines.
3199. Beechey. — Improvements in gas motor engines.
3414. Spiel — Improvements in petroleum and gas engines.
3471. Pope. — Improvements in gas engines.
3747. Holt — Regulator for supply of gas to motor engines.
3785. Atkinson — Improvements in gas engines.
3971. Mackenzie. — Improvements in gas engines.
4315. Daimler.— Improvements in motor engines worked by combustible
gases, or petroleum vapour, or spray.
4684. Garrett. — Improvements in motors worked by combustible gas or
vapour.
5519. Bickerton.— Improvements in gas regulators for supplying gas to gas
motors.
506 The Gas Engine
NO.
5561. Andrew. — Improvements in gas motor engines.
5971. Mills — Improvements in gas motor engines.
6047. Rigg — Improvements in engines worked by elastic or non-elastic
fluids, or by the explosion of mixed gases ; applicable also to appa-
ratus for pumping.
6565. Weatherhogg — Improvements in gas motor engines.
6763. McGhee & Magee — Improvements in gas motor engines.
6880. Macgeorge Improvements in and relating to gas engines.
6990. Campbell. — Improvements in gas engines.
7104. Warsop & Hill. — An improved apparatus for igniting the gas or ex-
plosive mixture in gas motor engines.
7500. Capitaine & Briinler.— Improvements in gas engines.
7581. Capitaine & Briinler, — Improvements in the production of a com-
pressed gaseous compound for use in gas motors and for other
purposes, and apparatus therefor.
7920. Dawson — Improvements in gas engines.
7929. Newton. — Improvements in gas motor engines.
8134. Crossley. — An improved gas engine.
8160. Wordsworth & Wolstenholme. — Improvements in gas engines.
8411. Humes. — Improvements in hydro-carburetted air engines.
8583. Newton. — Improvements in gas motor engines.
8584. Treeton — Improvements in or relating to gas engines.
8897. Sturgeon Improvements in gas engines.
9801. Col ton (Hartig). — An improved gas engine.
10227. Priestman & Priestman. — Improvements in the construction and
working of motor engines operated by the combustion of benzoline
or other liquid hydrocarbons.
10401. Justice (Hale). — Improvements in gas engines.
10786. Daimler — Improved vehicle propelled by a gas or petroleum motor
engine.
11290. Redfern (Smyers) — Improvements in gas engines or engines actuated
by the explosion or combustion of mixed gas or vapour and air.
11294. Clark (The Economic Motor Company, Incorporated).— Improve-
ments in gas engines.
11422. Magee — Improvements in gas engines.
11555. Cattrall & Storet. — Improvements in regulators for gas engines.
11558 Gillott. — Improvements in gas motors.
11933. Abel (Gas-Motoren-Fabrik Deutz).— An improvement in the slides
and passages of gas motor engines.
12424. Southall. — An improvement in gas motor engines.
12483. Clark (The Economic Motor Company, Incorporated) — Improve-
ments in gas engines.
12896. Schiltz — Improvements in gas and petroleum engines.
13163. Groth (Daimler) — Improvements in gas and oil motive power engines.
Appendix II 507
NO.
17309. Dinsmore Improvements in rotary air and gas motor engines.
13623. Royston Improvements in, and in connection with, motive power
engines actuated by the combustion of a mixture of gas or vapour
and atmospheric air..
14394. Nash Improvements in liquid fuel vapour engines and method of
operating the same.
14574. Black Improvements in the construction of steam and other motive
power engines of the horizontal and incline and vertical table class.
15194. Burgh and Gray Improvements in motors actuated by the expansion
of gases resulting from the combustion of fuel in the motor.
15243. Atkinson. — Self-starting valve for gas engines.
15475. Von Ruckteschell.— An improved explosion engine.
15525. Ashby — Improvements in gas engines.
15710. Johnson (Deboutteville & Malandin). — Improvements in governors or
regulators for gas and other motive power engines.
I5737- Rogers. — Improvements in gas engines.
15845. Bickerton Improvements in gas motor engines.
15874. Wilcox — Improvements in gas engines.
15875. Wilcox Improvements in gas engines.
15876. Wilcox — Improvements in gas engines.
15936. Wimshurst — An improved method of equalising the power given off
by gas or other engines or motors.
1886.
ii. Johnson (Deboutteville & Malandin). — Improvements in gas engines.
207. Butterworth.— Improvements in motors worked by combustible gas
or vapour.
478. P'airweather (Babcock). — Improvements in air or gas engines.
493. Nash. — Improvements in gas engines.
665. Magee — Improvements in gas motor engines.
942. Brine — Improvements in gas engines.
1394. Priestman & Priestman — Improvements in motor engines operated by
the combustion of liquid hydrocarbon.
1433. McGhee — Improvements in gas engines.
1464. Humes — Improved means for mixing and igniting combustible
charges operating liquid hydrocarbon engines.
1696. Welch & Rook — An improved gas engine.
1797. Shillito (Capitaine). — An improved method and means for cooling the
cylinders of gas, petroleum, hot air, and similar motors.
1958. Haddan (Jonasen). — Improvements in gas motors.
2140. Capitaine & Brlinler. — Improvements in oil, petroleum, naphtha, and
similar motors.
2174. Skene — Improvements in gas engines.
$o8 The Gas Engine
NO.
2272. Leigh (Spiel).— Improved supply valve gear for petroleum or gas
engines.
2447. Shaw.— Improvements in the construction of gas engines.
2653. Boulton & Perrett.— Combined steam and gas engines.
2993. Milhurn & Hannan — Improvements in motors worked by combustible
gas or vapour.
3010. Deacon — Improvements in and in connection with motive power
engines actuated by pressure due to heat of combustion.
3402. Fielding — A gas motor engine.
3473. Davy — An improvement in gas engines.
3522. Atkinson — Improvements in gas engines.
4234. Niel — Improvements in gas engines.
4460. Dawson — Improvements in gas engines.
4785. Hutchinson — Improvements in engines actuated by the thermo-
dynamic energy of petroleum and similar combustible fluids.
4881. Justice (Taylor) — Improved combined gas engine and fluid pump.
5597. Humes — Improved means for preventing 'back ignition' in hydro-
carbon engines.
5665. Bernardi — Improvements in and relating to gas engines or motors.
5789. Benz — Improvements in gas motors for wheeled vehicles and in their
application thereto.
5804. Abel. — Improvements in gas motor engines.
6161. Redfern (Gardie). — An improved motor, and apparatus for generating
gas therefor.
6165. Leigh (Spiel). — Improvements in petroleum and gas engines.
6551. Wright & Charlton Wright — Improvements in petroleum and such
like engines.
6612. Gillespie — Improvements in gas motor engines.
6670. Nash. — Improvements in construction and method of operating gas
engines.
7427. Rollason.— Improvements in gas engines.
7658. Nixon. — Improvements in gas engines having two pistons in the
same cylinder.
7936. Butterworth. — Improvements in motors worked by combustible gas.
8210. Roots. — A petroleum engine.
8436. Weatherhogg. — Improvements in petroleum and similar engines.
9563. Fielding. — Ignition apparatus for gas motor or oil motor engine.
9598- Johnson (Deboutteville & Malandin). — Improvements in apparatus
for carburetting air.
9866. Stuart. — Improvements in petroleum and other explosive engines.
10332. Boys & Cunynghame. — Reducing or preventing noise of escaping gas
or vapour.
10480. Schiltz. — Improvements in or connected with petroleum motors or
engines worked with liquid fuel.
Appendix II 509
NO.
11269. Humes. — Improvements in or applicable to motor engines operated
by the combustion of fluid hydrocarbon.
11285. Crossley. — Improvements in valves for gas and oil motor engines.
11576. Bolt. — Improvements in gas engines.
12068. Hutchinson and London Economic Motor and Gas Engine Co. — Im-
provements in motor engines worked by combustible gases or
petroleum vapour or spray.
1 2 1 34. Butterworth & Butterworth. — Improvements in engines in which power
is obtained by the ignition and expansion of a combustible mixture.
12368. Rollason. — Improvements in gas or vapour engines.
12640. Sutcliffe. — Improvements in utilising the waste heat of gas and com-
bustion explosive motor engines for heating water.
12912. Clerk. — Improvements in gas motors.
13229. Humes. — Improvements in and connected with motor engines
operated by the combustion of fluid hydrocarbon.
13517- Maccallum. — Improvements in and relating to the propulsion of navi-
gable vessels.
13655. Rockhill. — Improvements relating to flywheel guards.
13727. Newton (Murray). — Improvements in the construction of gas engines.
14034. Daimler. — Apparatus for effecting marine propulsion by gas or
petroleum motor engines.
14578. McGhee. — An improved gas motor engine, specially applicable for
use with mangling machines.
15307. Robson. — Improvements in gas engines.
15319. Stuart & Binney. — Improvements in gas, petroleum, and other hydro-
carbon explosive engines or motors.
15327. Taylor. — An improved gas motor engine.
15472. Southall — An improvement in gas motor engines.
15507. Wordsworth & Wolstenholme. - Improvements in gas or other
hydrocarbon motors.
1 5507 A. Wordsworth £ Wolstenholme. — Improvements in gas or other hydro-
carbon motors.
15764. Griffin — Improvements in apparatus for automatically shutting off the
gas supply of gas motor engines.
15955- Hearson. — Improvements in arrangements for utilising the vapour of
volatile liquid hydrocarbons for actuating motive power engines.
16779. Priestman & Priestman.— Improvements in the construction and
working of hydro-carburetted air engines, and in apparatus ap-
plicable thereto.
1887.
8. Turnock. — Improvements in apparatus for converting reciprocating
into rotary motion, and in the application of such apparatus to steam
and other fluid pressure engines.
510 The Gas Engine
NO.
125. Sterry & Sterry.— Improvements in explosive gas engines.
516. Newhall & Blyth. — Improvements in gas and other hydrocarbon
engines.
847. Abel (The Gas-Motoren-Fabrik Deutz) — Igniting apparatus for gas
engines.
888. Hosack. — Improvements in internal combustion ' heat ' engines.
1168. Charter, Gait & Tracy. — Improvements in gas engines.
1189. Abel (The Gas-Motoren-Fabrik Deutz).— Improvements in gas motor
engines.
1262. Benier. — Improvements in hot air engines.
1266. Adam. — Improvements in gas and other hydrocarbon engines.
1454. Priestman & Priestman. — Improvements in the construction and work-
ing of hydro-carburetted air engines.
1986. Pinkney. —Improvements in hammering, stamping, 'punching, and
other like machinery actuated by explosive gaseous mixture.
2194. Haddan (Gavillet & Martaresche) — Improvements in gas engine.
2236. Bamford.— Improvements in lubricators used for gas engines and other
purposes.
2368. Thomas. — Improvements in engines driven by gas, steam, petroleum,
and the like.
2520. Browett & Lindley. — Improvements in motor engines worked by gas
or hydrocarbon.
2631. Tellier. — Improvements in tramway and railway locomotives.
2783. Knight. — Improvements in engines worked by the heavier hydro-
carbons.
3109. Spiel. — Improvements relating to engines or motors chiefly designed
to be driven by means of carburetted air.
3934. Griffin. — Improvements in the arrangement and construction of gas
motor engines.
4160. Beechey. —Improvements in gas-bags or apparatus for regulating the
supply of gas to gas engines.
4403. Ross & McDowall. — Improvements in rotary engines and pumps.
4511. Ridealgh. — Improvements in gas engines.
4564. Sington. — Improvements in and relating to the traction or propulsion
of tramcars and road vehicles by means of gas and similar engines or
motors.
4757- Casper (Tavernier). — Improvements in gas and other engines operated
by explosive mixtures,
4843. Stevens. — Improvements in combined gas and compressed air
engines.
4923. Sturgeon. — Improvemerts in certain gas engines.
4940. Wallwork. — Improvements in self-acting mechanism or apparatus for
supplying lubricant to parts of gas engines and other machinery.
5°95- Johnson (La Societe des Tissages et Ateliers de Construction Diede-
richs). — Improvements in gas engines.
Appendix II 511
NO.
5336. Bernhardt.— Improvements in regulating apparatus for gas motor
engines.
5485. Hargreaves. — Improvements in and connected with internal combus-
tion thermo-dynamic engines.
5833. Crossley. — A combined gas motor engine and dynamo electric
machine.
5951. Priestman & Priestman. — Improvements in motor engines operated
by the combustion .of liquid hydrocarbon.
5981. Korting. — Improvements in gas motors.
6501. Dawson. — Improvements in engines worked by explosive mixtures:
7350. Faber. — Improvements in gas motors
7677. Davy. — An improved gas engine.
7771. Wastfield. — Improvements in and relating to gas engines.
7925. Wallwork & Sturgeon. — Improvements in gas engines.
8818. Beechey. — Improvements in gas motor engines.
9111. Haddan (Archat). — Improvements in gas, petroleum, and other
hydrocarbon engines.
9717. Ducretet. — Improvements relating to apparatus for filtering or purify-
ing oil in connection with gas and petroleum engines.
10176. Hahn. — Improvements in gas motors.
IOI76A. Hahn. — Improvements in carburettors for gas motors and other pur-
poses.
10202. H. C. Bull & Co. and H. C. Bull. — Improvements in and connected
with gas motors.
10360. Dougill. — Improvements in gas motor engines.
10460. Griffin. — Improvements in double cylinder gas motor engines.
11255. Justice (Hale). — Improvements in gas and pumping engines.
1 1 345- Lindley & Browett. — Improvements in gas motor engines.
11444. Abel (The Gas-Motoren-Fabrik Deutz). — Improvements in igniting
apparatus for gas motor engines.
11466. Wordsworth. — Improvements in gas or other hydrocarbon motors.
11503. Abel (The Gas-Motoren-Fabrik Deutz). — Improvements in motor
engines worked by combustible gas, vapour, or spray and air.
11567. Niel & Bennett. — Improvements in hydrocarbon engines.
1 1678. McGhee & Burt. — A new or improved combined mincing machine and
gas motor engine.
11717. Embleton. — Improvements in gas motor engines.
11911. Atkinson. — Improvements in gas engines.
12187. Abel (The Gas-Motoren-Fabrik Deutz).— Improvements in gas motor
engines.
12432. Priestman & Priestman. — Improvements in or applicable to motor
engines operated by the combustion of hydrocarbon vapour.
12591. Lane. — Improved method of applying or utilising compressed com-
bustible gases for the production of motive power.
5 1 2 The Gas Engine
NO.
12592. Hearson. — Improvements in and connected with the vaporisation of
volatile liquid hydrocarbons, and the utilisation of the vapour
thereof for actuating motive power engines, and apparatus or
arrangements for those purposes.
12696. List, List, & Kosakoff. — Improvements in petroleum engines.
12749. Charter, Gait, & Tracy — Improvements in gas engines.
12863. Korting.— Improvements in gas engines.
13436. Lea. — Improvements in gas engines.
13555. Knight Improvements in engines worked by mineral oils.
13916. Davy. — Improvements in gas engines.
14027. Barker Improvements in gas engines.
14048. Middleton.— A new or improved gas motor engine.
14269. Hutchinson Improvements in and relating to utilising the chamber
or space between the cylinder and jackets of engines or motors for
the purpose of vaporising oil in connection with steam, gas, oil, or
other engines or motors using heat as a source of power.
14952. Schmid & Bechfeld. — Improvements in gas engines.
15010. Crossley & Anderson. —Ignition apparatus for gas or oil motor.
15598. Butler Improvements in hydrocarbon motors, and in the method
of their application for the propulsion of tricycles and other light
vehicles.
15658. Davy.— Improvements in gas and other engines.
16029. Williams.— Improvements in gas motor engines.
16144. Williams.— Improvements in gas motor engines.
16257. Ravel £ Breittmayer. — Improvements in and relating to gas engines.
16309. Sturgeon. — Improvements in gas engines.
17108. Abel (The Gas-Motoren-Fabrik Deutz) — Improvements in motor
engines worked by combustible gas.
17353. Wall work £ Sturgeon. — Improvements in apparatus for governing the
speed of gas engines.
17686. Bickerton Improvements in the method of, and apparatus for, start-
ing gas engines.
17896. Abel (The Gas-Mctoren-Fabrik Deutz) — Apparatus for heating the
igniting tubes of gas motor engines.
1888.
270. Priestman and another. — Improved means for facilitating the starting
of hydrocarbon engines, and for regulating the ignition of the in-
flammable charges whereby same are operated.
512. Sington Improvements in gas, petroleum, and similar engines.
688. Abel (The Gas-Motoren-Fabrik Deutz) Improvements in igniting
apparatus for gas motor engines.
1336. Imray. — Improvements in apparatus for starting tramway cars.
Appendix II 513
NO.
1381. Blessing. —Improvements in gas and other hydrocarbon engines.
1705. Crossley. — Compound gas or oil motor engine.
1780. Butler. — Improvements in hydrocarbon motors.
1781. Butler. — Improvements in hydrocarbon motors.
2466. Quack. — Improvements in motor engines worked by combustible
gas or vapour and air.
2804. Johnson (La Societe Salomon). — Improvements in gas engines.
2805. Johnson (Deboutteville & Malandin). — Improvements in starting
gear for gas engines.
2913. Oechelhaeuser. — Improvements relating to gas engines.
3020. Abel (The Gas -Motor en -Fabrik Deutz). — Improvements in motor
engines worked by combustible gas or vapour and air.
3095. Abel (The Gas-Motoren-Fabrik Deutz). — Improvements in igniting
apparatus for gas or oil motor engines.
3427. McGhee & Burt. — Improvements in gas motor engines.
3546. Rollason & Hamilton — Improvements in and connected with gas
and vapour engines.
3756. Crossley. — Improvements in igniting apparatus for gas and oil motor
engines.
3964. Gase. — Improvements in the mode of working gas engines.
4057. Turner & Brightmore.— Improvements in the application of com-
pressed atmospheric air to motors.
4624. Crossley. — An improvement in valve and governing gear for gas or
oil motor engines.
4944. Wilson. — Improvements in or pertaining to combined arrangements
of gas engines and gas producers.
5204. Lake (Beuger). — Improvements in and relating to ignition apparatus
for gas, petroleum, or other engines or motors.
5628. Tavernier & Casper. — Improvements in and relating to gas and other
engines.
5632. Humes. — Improvements in or applicable to motor engines operated
by the combustion of hydrocarbon vapour.
5724. Abel (The Gas-Motoren-Fabrik Deutz) — An improvement in motor
engines worked by the combustion of spray of petroleum or other
combustible liquids.
5774. Rowden — Improvements in motors worked by gas or other com-
bustible bodies.
5914. Lake (Spiel). — Improvements in and relating to hydrocarbon
engines.
6036. Gase. — Improvements in gas engines.
6088. Thompson (Durand). — Improvements in and relating to engines or
motors, and to the production of carburetted air for driving the
same.
LL
514 The Gas Engine
NO.
6468. Korytynski. — Improvements in engines designed to produce motive
power through the consumption of inflammable vapours or gas.
6794. Stitt. — Improvements in or connected with mechanically propelled
, lifeboats, applicable also to other craft.
7521. Wordsworth. — Improvements in gas or liquid hydrocarbon motors.
7547. Browett & Lindley. — Improvements in motor engines worked by
gas or hydrocarbon.
7893. Schnell. — Improvements in motor engines actuated by a mixture of
gas, or the vapour of a hydrocarbon or hydrocarbons, and atmo-
spheric air.
7927. Stubbs. — Improvements in motor engines actuated by the combus-
tion of mixtures of combustible gas and air and the vapour of a
hydrocarbon or hydrocarbons, or other combustible mixtures.
7934. Southall. — Improvements in gas motor engines.
8009. Nelson. — Improvements in hydrocarbon engines.
8252. Johnston. — Improvements in motors to work with combustible gas or
vapour.
8273. Kostovitz. — Improvements in and relating to gas and hydrocarbon
engines.
8300. Deboutteville & Malandin. — Improvements in starting gear for gas
engines.
8317. Altmann — Improvements in petroleum motors.
9249. Deboutteville & Malandin. — Improvements in governors for gas
engines and other like motors.
9310. Roots. — Improvements in gas engines.
9311. Roots. — Improvements in hydrocarbon engines.
9342. Aria & Chemin. — Process for treating leather pistons to render same
impervious to action of petroleum and heavy oils.
9578. Dougill. — Improvements in gas motor engines.
9602. Abel (Gas-Motoren-Fabrik Deutz). — Improvements in valve appa-
ratus for gas and oil motor engines.
9691. Knight. — Improvements in engines worked by mineral oils.
9705. Rowden. — An improved motor actuated by the explosions of mixtures
of inflammable gases or vapours and atmospheric air.
9725. Middleton. — Improvements in flying machines, and apparatus for
propelling the same.
10165. Purnell. — An improved gas motor engine.
10350. Nash. — Improvements in gas engines.
10462. Williams. — Improvements in mechanism for regulating the supply of
gas or other fluid to gas or similar engines.
10494. Hall. — Improvements in motor engines operated by the combustion
of explosive mixtures of fluids.
10667. Binney & Stuart. — Improvements in petroleum and other hydrocarbon
explosive engines and motors.
Appendix II 515
NO.
10748. Campbell. — Improvements in gas motor engines.
10980. Hargreaves. — Improvements in internal combustion thermo-motors.
10983. Piers. — An improved form of engine adapted to tramcars and loco-
motives.
10984. Piers. — An improved method for starting gas engines and hot air
and petroleum engines, particularly when such engines are applied
to tramcars or locomotives.
11067. Roots. — Improvements in hydrocarbon or petroleum engines.
11161. Morris & Wilson. — Improvements in apparatus for the generation of
gas from hydrocarbon oils.
1 1 242. Barker. — Improvements in gas engines.
11614. Purchas & Friend. — Improvements in hydrocarbon motors.
12361. Hargreaves. — Improvements in internal combustion thermo-motor.
I2399- Charon. — Improvements in gas motors with variable expansion.
13414. Boult (Larrivel & Aeugenheyster). — Improvements in gas motor.
14076. Stuart & Binney. — Improvements in hydrocarbon explosive engines.
14248. Crossley, Holt & Anderson. — An improvement in gas motor engines.
14349. Abel (The Gas-Motoren-Fabrik Deutz). — Igniting apparatus for gas
and oil motor engines.
14401. Hearson. — Improvements in motive power engines actuated by the
firing of inflammable gas or vapour in admixture with air.
14614. Royston. — Improvements in and connected with internal combustion
heat engines.
14831. Williams. — Improvements in mechanism for governing the speed of
gas and similar motor engines.
15158. Richards. — Improvements in hydrocarbon engines, partly applicable
to other motor engines.
15448. Thompson (Regan). — Improvements in or relating to gas engines.
15840. Boult (Capitaine). — Improvements in or relating to gas motors.
15841. Boult (Capitaine). —Improvements in or relating to igniting apparatus
for gas motors.
15845. Boult (Capitaine). — Improvements in gas motors.
15846. Boult (Capitaine). — An improved friction clutch or coupling specially
applicable to gas motors.
15858. Jensen (Weilbach). — Improvements in apparatus for braking and re-
starting of rotating axles or shafts of tramcars, gas engines, and
other machinery.
15882. Roots. — Improvements in or connected with petroleum engines.
16057. Lindley & Browett.— Improvements in liquid hydrocarbon motor
engines.
16183. Simon. — An improvement in or connected with gas engines.
16220. Roots. — Improvements in gas engines.
16268. Lalbin. — Improvements in and relating to gas engines.
16605. Menzies. —Improvements in and relating to piston packing rings.
LL2
516 The Gas Engine
NO.
17167. Korting Improvements in gas and petroleum engines.
17413. Crossley & Anderson. — Improvements in igniting apparatus for gas or
oil motor engines.
18377. Shaw.— Improvements in gas and other explosive engines.
18761. Hargreaves. — Improvements in internal combustion thermo-motors.
19013. Pinkney. — Improvements in gas motor engines.
1889.
121. Boult (Capitaine). — Improvements in or relating to distributing
mechanism for gas motors.
441. Paton. — Improvements in appliances for starting gas and similar
engines.
708. Taylor. — An improved gas motor engine.
875. Repland (Niel). — Improvements in gas engines.
1603. Tavernier. — Improvements in and relating to engines.
J957- Publis. — Improvements in gas motors.
2144. Piers. — The application of gas and petroleum and like engines to
locomotive and other intermittent work.
2637. Miller. — Improvements in and relating to petroleum, oil, vapour,
gas, and other explosive power engines.
2649. Gardie. — An improved gas engine and gas generator therefor.
2760. Hartley. — Improvements in apparatus for measuring liquids.
2772. Smith. — Improvements in or relating to the starting of motive power
engines.
3331. Adams.— Improvements in engines and motors actuated by products
of combustion.
3525. Pinkney. —Improvements in gas engines.
3820. Williams. — Improvements in gas motor engines.
3887. Imray (Weilbach). — Improvements in brake apparatus for revolving
axles or shafts.
3972. Roots. — Improvements in gas engines.
4710. Oechelhaeuser. — Improvements in and relating to gas engines.
4796. Schimming. — Improvements in, and apparatus for, superheating steam
and applying the same to steam engines.
5072. Southall. — Improvements in gas or oil motor engines.
5165. Lake. — Improvements in and relating to gas or vapour engines for
the propulsion of ships and other purposes. (The Secor Marine
Propeller Company.)
5199. Millet. — Improvements in gas and other fluid pressure engines for
terrestrial and aerial propulsion.
5301. Theerman. — Improvements in motor engines operated by the ignition
of explosive mixtures of air and petroleum, or other hydrocarbon,
or gas.
5397. Nelson & McMillan — Improvements in gas motor engines.
Appendix II 517
NO.
5616. Abel (Gas-Motoren-Fabrik Deutz). — Improved mechanism for revers-
ing the motion derived from a motor shaft, applicable to the motor
engines of vessels and vehicles, and for other purposes.
6161. Partridge & Brutton — Improvements in means or apparatus for start-
ing gas and other engines and machines.
6296. Banki & Csonka — Improved valve motion for gas engines.
6682. Priestman and another — Improvements in or applicable to motor
engines operated by the combustion of hydrocarbon vapour.
6748. Cordenons. — Improvements in rotary engines.
6831. Knight — Improvements in engines worked by mineral oils.
7069. Ta vernier & Casper — Improvements in and relating to engines
worked by explosive mixtures.
7140. Tellier — Improvements in the production of motive power by the
employment of gas, steam, and vapour, and in apparatus employed
therefor, and for its utilisation.
7522. Sumner An electric ignition apparatus for gas, petroleum, oil, or
combustible vapour engines.
7533. Sumner. —An ignition apparatus for gas, petroleum, oil, or combusti-
ble vapour engines.
7594. Crowe & Crowe — Improvements in gas and hydrocarbon motive
engines.
7640. Lawson Improvements in gas engines.
8013. Weatherhogg. — Improvements in and relating to petroleum and
similar engines.
8778. Imray (Glaser). — Improvements in petroleum motor engines.
8805. Clerk. — Improvements in gas engines.
9203. Butler and others Improvements in and connected with motors in
which an explosive mixture of air and petroleum is used.
9685. Hunt & Howden. — Improvements in motors actuated by combusti-
ble gas or vapour.
9834. Roots Improvements in petroleum or hydrocarbon engines.
10007. Daimler.— Improvements in gas and petroleum motor engines.
10286. Rogers & Wharry. — Improvements in gas engines.
10634. Bull. - Improvements in petroleum and other explosive vapour or gas
engines.
10669. Rowden. — Improvements in gas motors.
10831. Leigh (Forest & Gallice). — Improvements in compound gas or petro-
leum engines.
10850. Wastfield. — Improvements in or relating to petroleum or hydro-
carbon engines.
11038. White & Middleton. — Improvements in gas engines.
11162. Williams.— An improved incandescent tube for firing the explosive
charges of gas and other similar motor engines.
11395. Hartley. — Improvements in hydrocarbon or petroleum engines.
5 1 8 'The Gas Engine
NO.
1 1926. Bull. — Improvements in vapour gas engines.
12045. Allison (McNett) — Improvements in combined gas engines and
carburetters.
12447. Hoelljes — Improvements in, and in the method of operating, gas
engines.
12472. Thompson (Covert). — Improvements in or relating to gas engines or
gas motors.
12502. Lanchester Improvements in apparatus for governing gas and other
motive power engines.
*3572. McAllen Improvements in gas or oil motor engines.
14592. Huntington — Improvements in vehicles.
14789. Hargreaves Improvements in internal combustion regenerative
thermo-motors, some of which said improvements are applicable to
gas and hot air engines.
14868. Binney & Stuart. — Improvements in hydrocarbon engines.
14926. Diederichs — Improvements in or connected with combustible vapour
engines.
16202. Green — Improvements in gas engines.
16391. Lindemann Improvements in gas and petroleum engines.
l^393- Girardet. — Improvements in means for generating and utilising gas
or vapour, and in apparatus therefor.
16434. Hamilton & Rollason — Improvements in and connected with gas or
vapour engines.
17008. Haedicke. — A combined gas and steam motor engine.
17024. Boult (Rotten). —Improvements in petroleum or similar motors.
17295. Niel & Janiot Improvements in gas motors.
17344. Lowne. — Improvements in atmospheric engines, partly applicable to
other motive power engines.
18746. Abel (The Gas-Motoren-Fabrik Deutz).— Improvements in igniting
apparatus for gas and oil motor engines.
18847. Barnett & Daly — Improvements in gas or vapour engines, and in
electric exploding devices, or apparatus for such engines.
19868. Lanchester. —Improvements in gas motor engines.
20033. Lindley & Browett — Improvements in hydrocarbon motor engines.
20115. Ford — Improvements in rotary gas engines, parts of which improve-
ments are applicable to other engines.
20161. Duerr. — Improvements in gas and petroleum motors.
20166. Frederking and another — Improvements in positive motion gear for
lift valves.
20249. Crist & Covert — Improvements in gas engines and igniters for the
same.
20482. Atkinson. — Improvements in internal combustion heat engines.
20703. Snelling. — Improvements in rotary engines to work with steam, air,
gas and other fluids.
Appendix II 519
NO.
20892. Abe (The Gas-Motoren-Fabrik Deutz) — Improved apparatus for
regulating the speed of gas and oil motor engines.
1890.
1150. Lindner. — Improvements in or connected with petroleum engines.
1586. Tavernier & Casper. — Improvements in or relating to the cylinders
and pistons of engines operated by explosive mixtures.
1943. Abel (The Gas-Motoren-Fabrik Deutz) — Improvements in motor
engines worked by oil vapour.
2207. Scollay — Improved means for regulating the admission of gas and
air in atmospheric burners, and for supplying gas engines.
2384. La Touche — Improvements relating to hot air engines.
2647. Lake (Beckfield & Schmid) Improvements in gas engines.
2919. Grob and others. — Improvements in petroleum engines.
4164. Abel (Gas-Motoren-Eabrik Deutz) Improvements in the means
and apparatus for governing gas and petroleum engines.
4362. Binns. — Improvements in gas motor engines.
4574. Kaselowsky Improvements in gas and petroleum motors.
4823. Otto. — Improvements in gas or oil motor engines.
5005. Baxter (Hoist) — Improvements in gas engines.
5192. Melhuish — Improvements in gas and petroleum motors.
5273. Otto — Improvements in gas or oil motor engines.
5275. Otto.— Improvements in petroleum or oil motor engine
5479. Lanchester. — Improvements in gas motor engines.
5621. King (Connelly) — Improvements in or connected with driving gear
for giving motion to tramcars and other vehicles propelled by
motors.
5933- Dheyne and others Improvements in gas engines operated by gas
generated from petroleum or other liquid hydrocarbons.
5972. Otto. — Improvements in gas and oil motor engines.
6015. Hamilton — Improvements in gas or combustible vapour motor
engines.
6113. Otto — Improvements in gas and oil motor engines.
6217. Griffin — Improvements in apparatus for producing combustible gas
for gas motor engines or other purposes.
6407. Dawson — Improvements in gas engines.
6910. Dorrington & Coates — Improvements in gas engines.
6912. Fielding Improvements in gas motor engines.
6990. Butler. — Improvements in motive engines operated by explosive mix-
tures of petroleum and air.
7 146. Stuart & Binney — Improvements in engines operated by the explosion
of mixtures of combustible vapour or gas and air.
7177. Mewburn (Proell and others). — Combined gas and compressed air
motors.
52O The Gas Engine
NO.
7626. Johnson (Lantsky). — Improvements in engines or motors actuated by
products of explosion or combustion.
8431. Seage & Seage.— Improvements in gas motor engines.
9496. Robson Improvements in gas or other motive power engines.
10051. Wilkinson — Improvements in apparatus for producing hydro-
carburetted air for motive power purposes.
10089. Beechey — Improvements in gas motor engines.
10642. Vogelsang & Hille — Improvements in valve gear of gas engines and
petroleum engines.
10718. Grob and others. — Improved means for effecting the ignition of vapour
in gas and petroleum motors.
10952. Griffin — -Improvements in apparatus for regulating and governing
the admission of gas and air into gas motor engines.
11062. Lake (Brayton) — Improvements in hydrocarbon engines.
11755. Richardson & Norris — Improvements in gas or vapour engines.
11834. Schiersand — An improved spring governor or regulator for gas and
other engines and motors.
12314. Holt.— An improvement in supply, exhaust, and governing apparatus
for oil motor engines.
12472. Stuart Improvements in compound hydrocarbon explosive engines.
12678. Justice (Baldwin) — Improvements in tramcars and motors.
12690. McGhee & Burt Improvements in and relating to gas motor
engines.
12760. Stallaert. — Improvements in motors adapted to be operated by ex-
plosives.
13019. Vermand.— Improvements relating to gas engines.
13051. Stuart Improvements in rotary motors.
13352. Ovens & Ovens Improvements in gas engines.
13594. Offen — Improvements in gas and other explosive engines.
14382. Hall Improvements in igniting arrangements for gas or oil motor
engines.
14549. Roots. — Improvements in gas engines.
14787. Robinson. — Improvements in gas or combustible vapour engines.
14900. Deboutteville & .Malandin — Improvements in or connected with gas
engines.
15309. Hartley Improvements in hydrocarbon or petroleum engines.
15525. Dheyne and others — Improvements in apparatus for use in connection
with engines operated by gas generated from petroleum or other
liquid hydrocarbon.
15526. Dheyne. — Improvements in engines operated by gas generated from
petroleum or other liquid hydrocarbon.
15994. Stuart & Binney. — Improvements in or connected with engines
operated by the explosion of mixtures of combustible vapour, or gas
and air.
Appendix II 521
NO.
16301. Cruikshank (White & Middleton). — Improvements in gas engines.
17167. Pinkney Improvements in and connected with engines operated by
gas generated from petroleum or other liquid hydrocarbons.
17299. Mottershead.— Improvements in or connected with gas engines.
17371. Higginson Improvements in gas engines.
18161. Sayer. — Improvements in gaseous pressure apparatus for producing
continuous rotary or rectilinear motion.
18401. Griffin. — Improvements in apparatus for igniting the charge in
petroleum and other hydrocarbon motors.
18645. Boult (Sharpneck) — Improvements in gas engine governors.
19171. Kaselowsky. — Improvements in ignition devices for gas motors.
19513. Lanchester — Improvements in the igniting and starting arrangements
of gas and hydrocarbon engines.
19559. Roots Improvements in petroleum or liquid hydrocarbon engines.
I9775- Lanchester — An improved ignition device for starting gas motor
engines.
19791. Lobet — Improvements in gas and other motive power engines.
19846. Lanchester — Improvements in uniting and starting gear for gas
engines.
19962. Griffin. — Improvements in petroleum and other liquid hydrocarbon
motors.
20888. Holt — Improvements in motor engines worked by gas, or by oil or
other vapour.
21165. Lentz and others — A single-acting gas motor engine.
1891.
103. Pinkney. — Improvements in and connected with engines operated by
gas generated from petroleum or other liquid hydrocarbon.
no. Carling. — An improvement in gas engines and other like motors.
191. Gray. — Improving engines actuated by the explosion of a mixture of
air with the vapour of petroleum or other hydrocarbons, or of tar,
creosote, or other liquid, which when heated are more or less vola-
tile, and the vapour of which, when mixed with air, forms an ex-
plosive mixture.
227. Bickerton Improvements in gas engines.
297. Bickerton. — Improvements in governors for gas engines.
383. Boult (Berliner Maschinenbau Actien Gesellschaft).— Improvements
in or relating to the valve gear of gas, petroleum, and other similar
engines.
741. Adams. — Improvements in engines, motors, and pumps.
816. MacCallum. — Improvements in gas, petroleum, and like engines.
-834. Miller Improvements in petroleum, oil, vapour, gas, and other
explosive power engines.
970. Williams. — Improvements in gas motor and similar engines.
522 The Gas Engine
NO.
1083. Robinson. — Improvements in gas or combustible vapour engines.
1299. Williams.— Improvements in gas motor engines.
1447. Weatherhogg. — Improvements in gas and hydrocarbon motor engines.
1903. Abel (Gas-Motoren-Fabrik Deutz). — Improvements in gas and oil-
motor engines.
2053. Gray. — Improvements in vaporisers for generating petroleum and
other hydrocarbon vapours for use in motors and engines.
2815. Rouzay. — Improvements in gas or petroleum engines.
2976. Hughes (Cordenons) Improvements in gas engines.
3261. Weiss. — Improvements in petroleum or oil motor engines.
3350. Coffey. — An improved gas engine.
3669. Rockhill. — An improved gas engine.
3682. Wertenbruch. — Improvements in or connected with gas and other
hydrocarbon engines and the pistons (or rings) thereof.
3830. Priestman £ Priestman. — Improvements in or applicable to hydro-
carburetted air engines.
3948. Trewhella. — Improvements in apparatus for condensing and utilising
the residue of gases exploded to form a vacuum in engines propelled
by gas or other explosive material.
4004. Dawes. — A new or improved apparatus to be used for the starting of
gas or other engines.
4142. Priestman & Priestman. — Improvements in hydro-car buretted air
engines.
4222. Lanchester Improvements in gas engines.
4355- Campbell. — Improvements in gas motor engines.
4535. Griffin. — Improvements in governing gas motor engines and in con-
nection therewith.
4771. Cooper. — Improvements in gas and vapour engines.
4862. Lindemann. — Improvements in gas and petroleum engines.
5158. Vanduzen. — Improvements in gas and gasoline engines.
5250. Love & Priestman Bros., Ltd — Improvements in or applicable to-
motor engines operated by the combustion of hydrocarbon vapour
or gas and by the expansion of readily liquefying gases.
5490. Higginson.— Improvements in gas engines.
5663. Fachris. — An improved motive power engine, actuated by explosives.
5747. Skene. — An improved fluid pressure regulator.
6090. Bickerton — Improvements in gas motor engines.
6410. Day. — Improvements in gas engines.
6578. Barclay. — Improvements in and relating to gas engines.
6598. Ridealgh & Welford. — Improvements in gas or vapour engines.
6717. Abel (The Gas-Motoren-Fabrik Deutz) — Improvements in apparatus
for supplying oil or other liquids under a constant head or pressure.
6727. Van Rennes. — Improvements in petroleum engines.
Appendix II 523
NO.
6949. Key. — Improvements in and relating to the treatment of the discharge
gases from gas engine cylinders.
7047. Purnell. — A governor for gas and oil motor engines.
7157. Altmann. — Improvements in governors for gas and petroleum motors.
7313. Pinkney Improvements in engines worked by the explosion of gas.
8032. Horn (Vanduzen & Vanduzen). — An improved gas engine.
8069. Capitaine. — Improvements in gas motors.
8251. Barrett & Ticehurst. — Improvements in motor engines actuated by
explosions.
8289. Hardingham (Clefand). — An improved rotary engine.
8469. Abel (Gas-Mot oren-Fabrik Deutz). — Improvements in gas and oil
motor engines.
8821. Shillitto (Grob, Schultze & Niemczik). — Igniting tubes for gas and
petroleum motors.
9006. Boult (Levasseur) — Improvements in gas, petroleum, and carburetted
air engines.
9038. Southall. —Improvements in gas and oil motor engines.
9247. Day. — Improvements in gas or vapour engines.
9268. Bosshardt (Huntington). — Improvements in governors and valve
movements for gas engines.
9323. Huelser (J. M. Grob & Co.). — A new or improved gasifying con-
trivance for petroleum motors.
9805. Hawkins. — Improvements relating to vibrating engines, applicable to
pumps or blowers.
9865. Dawson. — Improvements in gas engines.
9931. Withers & Covert. — Improvements in or relating to vibrating gas>
engines.
10298. . Crossley & Holt. — Improvements in oil motor engines.
10333. Fiddes & Fiddes. — Improvements in gas motor engines.
11132. Irgens — Improvements in and relating to gas or petroleum engines
or motors.
11138. Pinkney. — Improvements in or connected with engines worked by
gas generated from petroleum or other liquid hydrocarbon.
11628. Held. — A new or improved pressure regulator for gas engines.
11680. Kasclowsky Improvements in gas and petroleum engines.
11851. Wellington. — An improved ignition tube for gas and like engines.
11861. Lanchester. — Improvements in gas engine starting arrangements.
12330. Settle. — Improved means for actuating road or tram cars and lake or
other boats.
12413. Clerk. — Improvements in gas engines.
12981. Menard.— Improved method and means for firing the charges of gas
engines.
14002. King (Connelly) — Improvements in gas motors.
524 The Gas Engine
NO.
14133. Weyman & Drake. — Improvements in governing and regulating the
supply of oil to petroleum or hydro-carbon motors.
14134. Watkinson. — Improvements in thermo-dynamic machines and in
apparatus and appliances connected therewith.
14209. Johnson (Genty). — Improvements in non-return valves.
14269. Huelser (Grob & Co.).— Improvements in gas and petroleum motors.
14457. Waller. — An improved apparatus for exhausting gas.
14519. Abel (Gas-Motoren-Fabrik Deutz). — Improvements in igniting appa-
ratus for gas and oil motor engines.
14945. Lanchester. — Improvements in gas governors.
15078. Williams. — Improvements in gas and similar motor engines.
16404. Clerk Improvements in gas engines.
17033. Shiels Improvements in apparatus for automatically regulating the
temperature of the water used in cooling the cylinders of gas and
oil engines.
17073. Hornsby & Edwards — Improvements in explosion engines.
17364. Evers Improvements in gas motor engines.
17724. Abel (Gas-Motoren-Fabrik Deutz) — Improvements in valve appa-
ratus for gas and petroleum motor engines.
17815. Evans — Improvements in gas engines.
17955. Pinkney — An improved metallic alloy more especially intended for
use for gas or petroleum engine igniters, or like articles subjected
to great heat.
18020. Shaw & Ashwonh — Improvements in gas engines.
18276. Walch (Dorrington & Coates) — Improvements in valve gears for gas
engines.
18424. Lee — Improvements in gas and hydrocarbon motor engines.
18621. Roots & Seal — Improvements in or connected with internal com-
bustion engines.
18640. Weyman, Hitchcock & Drake — Improvements in gas and oil hydro-
carbon engines.
18715. Earnshaw & Oldfielcl — Improvements in and connected with valves
of gas engines.
18788. Clerk. — Improvements in starting gear for gas engines.
19086. McGhee & Burt — Improvements in and relating to gas motor
engines.
19275. Roots. — -Improvements in petroleum or liquid hydrocarbon engines.
19318. Barren — Improvements in or appertaining to gas engines.
19517. Fielding An improved method of starting gas engines.
19772- Johnson (Pieper). — Improvements in feed pumps for petroleum
engines.
19773- Johnson (Pieper) Improvements in the means for regulating the
temperature of evaporators of petroleum engines.
19811. Ridealgh — Improvements in gas and petroleum engines.
Appendix II 525
NO.
20262. Robinson Improvements in gas or combustible vapour engines.
20745. Robinson. — Improvements in gas or combustible vapour engines.
20845. Perrollaz Improvements in lubricators.
20926. Knight. — Improvements in engines worked by heavier hydrocarbons.
21015. Weyman, Hitchcock & Drake Improvements in oil or hydro-
carbon motors.
21229. Weyman, Hitchcock, & Drake.— Improvements relating to oil or
hydrocarbon motors.
21406. Lanchester — Improvements in gas engines.
21496. Hartley & Kerr. — Improvements in gas engines.
21529. Miller. — Improvements in valve gear for gas and other engines.
22559. Leigh (Forrest & Gallice). — Improvements in gas and petroleum
engines.
22578. Burt. — New or improved starting, stopping, and reversing gear for
machinery driven by gas or vapour engines.
22834. Seek — Improvements in gas and hydrocarbon engines.
22847. Abel (The Gas-Motoren-Fabrik Deutz). — Improvements in petroleum
or oil motor engines.
1892.
112. Richardson. —Improvements in the details of gas and vapour
engines.
260. Edwards (Petit & Blanc). — Improvements in the means of heating
the charge in gas and like engines.
520. Higginson — Improvements in gas engines.
524. Wilkinson. — Improvements in the working of gas engines.
826. Rankin & Rankin. — Improvements in petroleum and other hydro-
carbon motors.
919. Noble £ Brice — Improvements in lubricators for use in connection
with gas, oil, or other explosive engines.
926. Simon. — Improvements connected with gas and like engines.
1203. Southall. — Improvements in supply and discharge valves for gas or
oil motor engines.
1246. Brooks £ Holt. — Improvements in or additions to gas and vapour
engines or motors.
1768. Richardson & Norris.— -Improvements in gas engines.
1814. Schwarz. — An improvement in or connected with gas engines.
1879. Barker & Rollason. — Improvements in and appertaining to gas-bags
for gas engines.
2181. Atkinson. — Improvements in self-starting apparatus for gas and other
internal combustion motors.
2492. Atkinson. — Improvements in internal combustion engines.
2495. Swiderski. — An improved oil or gas motor.
526 , The Gas Engine
NO.
2728. Abel (Gas-Motoren-Fabrik Deutz). — Improvements in gas or oil motor
engines.
2854. Leigh (Spiel). — Improvements in liquid hydrocarbon engines.
2862. Crossley & Bradley.— Improvements in starting and igniting appa-
ratus for gas or oil motor engines.
3047. Instone.— An improved oil or gas engine.
3156. Bradford. — Improvements in fluid pressure motive power engines.
3165. Harris.— Improvements in tubes and apparatus for igniting gas,
petroleum and vapour engines by intermolecular combustion.
3203. Pinkney. — Improvements in or connected with gas engines.
3292. Czermak, Bergl, & Hutter — Improvements in gas motor engines.
3417. Humpidge, Humpidge, & Snoxell.- Improvements in gas motor
engines.
3574. Robert. — Improvements in and relating to gas engines.
3909. Stuart & Binney. — Improvements in hydrocarbon engines.
4078. Bickerton — Improvements in governors for gas engines.
4189. Hamilton Improvements in gas motor engines.
4210. Lanchester — Improvements in gas engine details.
4347. Bell & Richardson — Improvements in portable petroleum or liquid
fuel engines.
4352. Richardson & Norris.— Improvements in and appertaining to combus-
tion chambers of petroleum or hydrocarbon engines.
4374. Lanchester — Improvements in gas and petroleum engines.
4375. Richardson & Norris. — Improvements in the oil-supplying arrange-
ments of petroleum and other hydrocarbon or liquid fuel engines.
5445. Clerk. — Improvements in gas engine governors and valve gear.
5740. Bilbault. — Improvements in and relating to gas and petroleum
engines.
5819. Michels (Grob & Co. ) — Improvements in feeding devices for petroleum
motors.
5972. Bell & Richardson.— Improvements in semi-portable petroleum or
liquid fuel engines.
6240. Owen Improvements in motors to be operated by either gas or liquid
hydrocarbons.
6284. Chatterton. — Method according to which steam and afterwards gas
are used as working fluids in the same cylinder for the generation
of power.
6655. Morani. — Improvements in gas motors.
6828. Adams. — Improvements in rotary engines, motors and pumps.
6872. Shillito (Swiderski & Capitaine) — An improved petroleum motor.
6952. Dawson. — Improvements in gas engines.
7047. Courtney (Briienler) — Improvements in petroleum engines.
7241. Diesel. —A process for producing motive work from the combustion
of fuel.
Appendix II 527
NO.
7943. Sennett & Durie. — Improvements in the methods connected with the
production of supply of steam and gases, and in the utilisation there-
of in engines for producing motive power, and in the apparatus
therefor.
8128. Hornsby & Edwards. Improvements in engines actuated by the
explosion of combustible mixtures.
8401. Pollock. — Improvements in gas engines.
8538. Beugger. — Improvements in or applicable to gas and hydrocarbon
engines.
8678. Johnson (Genty). — Improvements in furnace gas engines or aero-
thermic motors.
8733. Griffin. — Improvements in or in connection with heating the igniting
apparatus of petroleum or other liquid hydrocarbon engines.
9121. Guillery. — An improved rotary motor, applicable also for use as a
pump, ventilator, or the like.
9161. Robinson. — Improvements in gas or combustible vapour engines.
9439. Beugger Improvements in petroleum and gas motors.
9448. Ogle. — Improvements in the means for igniting the charges in the
cylinders of explosion engines.
9674. Magee — Improvements in gas motor engines.
10091. Seek. — Improvements in or connected with hydrocarbon motors.
10254. Hamilton. — Improvements in valve operating and governing me-
chanism of gas and oil motor engines.
10437. Holt — An improvement in igniting apparatus for gas and oil motor
engines.
11141. Weyman, Hitchcock, & Drake. — Improvements in hydrocarbon
motors and in apparatus and appliances connected therewith.
11598. Thompson (O' Kelly). — Improvements in or relating to tramcars and
in motors therefor.
11708. Hitchcock & Drake. — Improvements in oil engines and the like
hydrocarbon motors.
11928. Webb. — Improvements in gas engines.
11936. Clerk. — Improvements in starting gear for gas and like engines.
11962. Hornsby, Edwards & Gibbon. — Improvements in engines actuated
by the explosion or burning of combustible mixtures.
12165. Anderson. — Improvements in gas and oil motor engines.
12183. Boult (Charter). — Improvements in gas or similar engines.
13077. Davy Improvements in gas engines.
13088. Johnson (Hille). — Improved mixing valve for petroleum and like
motors.
13117. Clerk. — An improved method of operating, and improvements in,
gas or petroleum hammers, gas pumps, gas punching, riveting
or cutting machines, in part applicable to gas or petroleum
engines.
528 The Gas Engine
NO.
13204. Abel (Gas-Motoren-Fabrik Deutz) — Improvements in gas and oil
motor engines.
13859. Binns. — Improvements in gas engines.
13939. Sayer. — A gas or similar motor for stationary or locomotive purposes.
14317. Von Oechelhauser & Junkers. — Improvements in and relating to gas
engines.
14650. Hogg & Forbes. — Improvements in hydrocarbon engines.
14713. De Susini. — -Improvements in motor engines worked by either vapour
or other volatile fluids in combination with a gas motor engine for
the utilisation of the waste heat thereof.
15247. Piers. — Improvements in gas engines.
15417. Weyman — Improvements in and connected with petroleum and like
engines.
16308. May bach. — Improvements in the method of, and the apparatus for,
effecting a continuous circulation and cooling of liquids employed
in motors and compressors.
16339. Griffin. — Improvements in liquid hydrocarbon and other motor
engines.
16365. Briggs & Sanborn. — An improved lubricating cup.
16379. Briinler. — Petroleum motor contrivance for pressing the petroleum into-
the gasificator by means of the air current introduced for the forma-
tion of the mixture.
16380. Brunler — Improvements in rotating petroleum motors.
16381. Brunler. — Petroleum motor.
16382. Brunler. —Improvements in evaporating devices for cooling gas and
petroleum motors, the cylinders and pistons of which are rotating
round a stationary crank.
16413. Redfern (La Societe Anonyme des Moteurs Thermiques Gardie),—
Improvements in and connected with gas engines or motors.
16986. Whittaker. — Improvements in and connected with ignition tube for
gas engines.
17277. Andrew, Bellamy & Garside. —Improvements in apparatus for govern-
ing the speed of gas, oil and other similar motor engines.
17391. Fairfax (Sohnlein). — Improvements in petroleum motors.
17427. Hartley & Kerr. — Improvements in compound engines, and in part
applicable to other gas engines.
17632. Held. — Improvements in petroleum and like engines, applicable to
fire extinguishing and other purposes.
17732. Paton. — Improvements in gas engines.
18020. Sou thall.— Improvements in gas and oil motor engines.
18109. Southall. — Improvements in gas and oil motor engines.
18118. Gilbert-Russell — Improvements in explosion engines.
18513. Cock. — An improvement in gas engines.
Appendix II 529
NO.
18808. Stroch. — Improvements in or connected with petroleum or other
hydrocarbon motors.
20088. Dowie £ Handyside.— A gas engine governor gear.
20413. Ryland. — Improvements in explosion engines.
20660. Weyman & Ellis. — Improvements in utilising the heat taken up by
the water employed for cooling the cylinders of gas, oil, or other
hydrocarb'on motors.
20683. Pinkney. — Improvements in gas engines.
20802. Andrew & Bellamy. — Improvements in gas, oil, and similar motor
engines.
20803. Andrew & Bellamy. — Improvements in gas, oil, and similar motor
engines.
21342. Priestman & Priestman. — Improved means for facilitating the start-
ing of hydro-carburetted air engines.
21475. Enger. — Improvements in gas engines or motors.
21534. Altmann — Improvements in and connected with spray apparatus for
hydro-carburetted air engines.
21857. Winckler (Jastram). — An improved arrangement for feeding oil
engines with oil in a duly regulated manner.
21858. Winckler (Jastram) — An improved reversing gear for a propeller
worked by engine power, with a reversing counter-shaft revolving
in an opposite direction to the main shaft.
21917. Wetter (Rademacher). — Process and apparatus for igniting the com-
bustible charges or gas mixtures of gas and oil motcrs.
21952. Diirr. — Improvements in hydrocarbon engines.
22664. Stuart & Binney — Self-starting mechanism for hydrocarbon engines,
22797. Weyman, Hitchcock, & Drake Gear for transmitting and revers-
ing the power given off by gas and oil motor engines.
23323. Knight Improvements in oil and gas engines.
23786. Roots Improvements in or connected with internal combustion
engines.
23800. Sennett & Durie — Improvements in the methods and means of
cooling, heating, and lubricating cylinders, such as those of gas
and steam engines, air compressors, and the like, and of equalising
the motion of the piston therein.
24065. Best. — Improvements in gas engines and in their application to motor
vehicles.
1893.
108. Fielding. — An improved double-cylinder gas or oil motor engine.
153. Wetter (Gerson & Sachse). — Method of varying the strength of the
explosion charge or the ratio between the constituents of the gas
and air mixture in gas engines.
M M
53O The Gas Engine
NO.
531. Shuttleworth and others.— Improvements in furnace lamps for oil
and gas engines.
608. Sabatier and others. — Improvements in gas and petroleum engines.
735. Abel (Gas-Motoren-Fabrik Deutz). — Improvements in gas and oil
motor engines.
779. Shiels.— Improvements in apparatus for automatically regulating the
temperature of the water used in cooling the cylinders of gas and
oil engines.
1070. Dawson. — Improvements in gas engines.
1277. Burt & McGhee. — Improvements in and relating to gas or ex-
plosive vapour motor engines.
21 10. Dixon — An improvement or improvements in gas engines.
2523. Mellin & Reid. — Apparatus for deodorising the exhaust of gas or
oil motor engines.
2596. Lanyon (Martin).— An improved hydrocarbon motor.
2788. Evans. — Improvements in gas engines.
2851. Bellamy Improvements in gas and similar motor engines.
2912. Weyman. — Improvements in or connected with lamps and vaporisers
for oil engines. .
3332. Hartley & Kerr. — Improvements in gas engines.
3401. Davy — Improvements in gas engines or other internal combustion
engines.
3971. Hartley & Kerr — Improvements in compound gas and like engines.
4327. Heys (Langensiepen). — A new or improved admission valve for gas
or oil engines
4564. Bellamy. — Improvements in gas and similar motor engines.
4696. Davy. — Improvements in gas and other internal combustion engines.
5005. Rollason.— A device for preventing the bursting of gas engine and
other water -jacketed cylinders or pipes by the freezing of the
water.
5256. Lake (Backeljau) — Improvements in explosive gas actuated pump.
5456. Trewhella. — Corrugated cylinders for internal combustion engines.
6093. Bellamy. — Improvements in gas and similar motor engines.
6204. Sayer. — Improvements in explosive and pressure elastic and non-
elastic turbine engines.
6453. Okes Improvements in internal combustion engines.
6534. Berk — Improvements in or connected with gas and oil engines.
7023. Owen Improvements in or in connection with self-generating
vapour burners, or apparatus for vaporising liquid hydrocarbons
for heating, lighting, or other purposes.
7064. Bellamy. — Improvements in gas and similar motor engines.
7292. Walker. — Exhaust scrubber for petroleum and other motors having
offensive or injurious exhaust.
7426. Dawson. — Improvements in gas engines.
Appendix II 531
NO.
7433. List and others. — Improvements in and connected with what are
commonly known as petroleum or oil engines.
7466. Burt. — Improvements in variable speed and reversing mechanism for
gas or vapour or other motors.
8095. Morcom. — Improvements in working motive power engines, and in
apparatus actuated by combustible gases to be employed for that
purpose, and for other purposes.
8158. Lindahl — Improvements in or relating to admission valves for petro-
leum or similar motors.
8409. Wilkinson — Improvements in and relating to gas, oil, and like
power motors.
8639. Drake. — Improvements in hydrocarbon engines.
8864. Robinson, A. E. & II. — Improvements in oil or gas engines.
8967. Crouan — Improvements in gas and other motive power engines.
-9181. Abel (Gas-Motoren-Fabrik Deutz). — Improvements in gas and oil
motor engines.
9216. Okes Improvements in internal combustion engines.
9549. Briickert & Delattre. — Improvements in rotary motors applicable
also as pumps.
9618. Roots. — Improvements in internal combustion engines.
10240. Gessner. — Improvements in steam and other engines and pumps.
10274. Abel (Gas-Motoren-Fabrik Deutz). — Improvements in valve gear for
gas and petroleum motor engines.
10310. Hartley & Kerr. — Improvements in gas and like engines.
10801. Peebles. — Improvements in or connected with gas or vapour motors.
12330. Grove. — Improvements in heating lamps applicable to hydrocarbon
engines, and apparatus therefor.
12388. List and others.— Improvements in what are commonly known as
petroleum or oil engines.
12427. Dougill. — Improvements in gas and explosive vapour motors.
12600. Drysdale. — Improvements in valves and atomising apparatus for
hydrocarbon engines.
12732. Morgan. — Improvements in combustible vapour engines, and in
their accessories.
12843. Priestman, W. D. & S. — Improvements in or applicable to internal
combustion engines.
12917. Pullen. — An improved oil, spirit, gas, or steam motor.
13282. Furneaux & Butler. — Improvements in starting apparatus for gas and
other motors.
13518. Fiddes, A. & F. A. — Improvements in gas and vapour motor engines
and the like.
14212. Smethurst and others — Improvements in methods of, and apparatus
for, applying combustible mixtures of air and gas or inflammable
vapour to driving motive power engines.
MM2
532 The Gas Engine
NO.
14454. Bickerton. — Improvements in starting apparatus for gas engines.
14546. Boult (The C.D.M. Niel). — Improvements in or relating to automatic
starting gear for motors operated by explosion.
14558. Hornsby & Edwards. — Improvements in engines operated by the
explosion of mixtures of combustible vapour or gas and air.
14572. Thompson (Diirr). — New or improved vaporisers for petroleum motors.
14891. Boult (La S. F. des M. C.).— Improvements in or relating to petro-
leum, gas, or oil engines.
15199. Campbell Improvements in oil and gas motor engines.
15359. Bellamy. — Improvements in travelling cranes.
15405. Fryer. — Improvements in valve gear for the ' Clerk ' and like type of
gas engine in .which a separate air and gas pump is employed.
15900. Boult (Brauer & Windnitz). — Improvements in rotary engines and
pumps.
15947. Simms. — Improvements in or connected with whistles or the like for
explosion engines.
16072. May bach. — Improvements in the method of producing the explosive
mixture in hydrocarbon engines.
16079. Tipping. — Improvements in rotary pumps, blowers, and engines,
also applicable for measuring fluids.
16290. Qurin. — Adjustable cam.
16410. Spiel & Spiel.— Improvements in hydrocarbon engines.
16575. Drake.— Improvements in the vaporisers and ignition tubes of oil
engines.
16751. Briinler. — Device in gas or petroleum engines with slow combustion
for insuring the maintenance of the combustion.
16752. Briinler Process for insuring the commencement of the ignition in
gas and petroleum engines.
16900. Crossley & Atkinson Improvements in internal combustion engines.
16985. Maybach. — Improvements in the method of igniting the explosive
mixture of hydrocarbons.
17784. Shuttleworth and others — Improvements in and for connecting-
together lamps and vaporisers.
18152 Sherrin & Garner. — Improvements in cylinders and pistons for gas
and other heat engines.
20007. Ryland. — Improvements in explosive engines.
20808. Priestman, W. D. & S. — Improved means applicable for use in mixing
liquids with gases in the manufacture of vapour.
21 1 20. Hamilton. — Improvements in gas motor engines.
21775. Briinler. — Process for obtaining a compression in gas and petroleum
engines with slow combustion.
21908. Barclay. — Improvements in and relating to sight-feed lubricators.
22181. Roots. Improvements in internal combustion engines.
22753. Pinkney. — Improvements in internal combustion engines.
Appendix II 533
NO.
23°75' Crossley £ Atkinson. — Improvements in gas or internal combustion
engines.
23175. Stoke. — Outlet valve motion for gas and petroleum engines.
23379- Wattles. — Improvements in gas engines.
23571. Roots. — Improvements in internal combustion engines.
.23735. Sintz and others. — Improvements in gas and other explosive engines.
24258. Durand. — Improvements in or relating to explosion engines.
24384. Hamilton. — Improvements in gas motor engines.
24584. Crossley & Hulley, — Improvements in internal combustion oil engines.
-24612. Sitton. — Improvements in oil engines.
24666. Campbell. — Improvements in gas motor engines.
1894.
263. Lindemann. — Improvements in gas or petroleum motors.
408. Abel (The Gas-Motoren-Fabrik Deutz). — Improvements in gas and
oil motor engines.
573. Dulier. — A method of and apparatus for generating elastic fluid for
working engines.
752. Lake (Die Firma Fried. Krupp). — Improvements relating to distri-
buting and igniting devices for gas, petroleum, and like engines.
778. Campbell. — Improvements in oil and gas motor engines.
1 121. Meacock. — Improvements in engine starters.
1581. Benier. — Improvements in and relating to gas engines.
2064. Foster. — Improvements in gas and other internal combustion engines.
2540. Fidler. — The utilisation of exhaust heat from gas, oil, tar, or spirit
engines.
2593. Lake (Grant). — Improvements in gas engines.
2656. Bellamy. — Improvements in gas and similar motor engines.
3122. Weyland. — Improvements in vaporisers for petroleum motors.
3303. Decombe and Lamena. — Improvements in actuating or operating the
valves of steam and other motive power engines.
3485. Davy. — Improvements in gas and other internal combustion engines.
4301. Holt. — A method of working valves of gas and oil motors, and
apparatus for that purpose.
4312. A. & F. A. Fiddes. — Improvements in or connected with internal
combustion motors.
4959. Singer. — Improvements in gas engine valves.
.4960. Singer. — Improvements in double acting compression gas engines or
oil engines.
5218. Rollason. — Improvements in the governing and construction of gas
engines.
5493. Southall. — Improvements in gas and oil motor engines.
5577. Capitaine. — An improved petroleum motor.
534 The Gas Engine
NO.
5680. Briinler. — Device for injecting the petroleum in four-stroke petro-
leum engines with two air inlet valves.
5681. Mitchelmore. — Improvements in hydrocarbon engines.
5843. Thomson, Yates, J. P. Binns, & H. G. Binns.— Improvements in
gas and oil engines.
6122. Hornsby & Edwards. —Improvements in explosion engines.
6138. Reid (Bray ton). — Improvements in oil and gas engines.
6364. Adams. — Improvements in gas, oil, and steam engines.
6647. Eaton. — An improved combined steam and gas generator and engine..
6755. Low. — Improvements in gas engines.
7023. Skene. — Improvements in gas and oil vapour engines.
7294. Farmer. — Improvements in gas and like engines.
7357- Schwarz. — A new or improved explosion engine.
7485. Merry weather & Jakeman. — Improvements in motor engines to be
worked with gas or vapour such as petroleum vapour.
7538. Roots. — Improvements in oil engines.
7542. Wolfmliller and Geisenhof (amended).— Improvements in and relat-
ing to motor-propelled velocipedes.
7630. Butter. — Improvements in means for operating and controlling the
valves of steam, gas, or oil engines.
8041. Adams. — Improvements in exploding chambers or receptacles, and
apparatus connected therewith, for oil, gas, or similar engines,,
motors, or pumps.
8295. Holt. — Improvements in gas motor or oil motor cars.
8668. Hogg & Grove. — Improvements in oil or gas engines.
9305. Dickinson. — Improvements in or relating to gas or vapour engines.
9403. Scott. — Improvements in pumps for oil engines or other purposes.
9723. Sondermann.— Improvements in and connected with the cylinders of
engines, motors, and compressers.
9788. Briinler. — Improvements in petroleum engines.
9889. J., S., F., £ E. Carter. — Improvements in and connected with
petroleum oil engines.
10034. Haddan (Piguet & Company). — An improved method of and appara-
tus for obtaining motive power by means of explosions.
10113. Holt. — Improvements in gas motor engines.
10451. Piers. — Improvements in or connected with locomotive engines, or
other engines subject to intermittent work or varying loads, &c.
10452. Piers. — Improvements in or connected with locomotive engines, or
other engines subject to intermittent work or varying loads, &c.
10511. Thompson (Schoenner). — Improvements in toy motors.
10623. Gibbon. — Improvements in petroleum or hydrocarbon engines.
10788. Henriod-Schweizer. — Improvements in gas and hydrocarbon engines-
or motors,
inoi. Howard, Bousfield & Bastin.— Improvements in explosion engines.
Appendix II 535
NO.
11108. Davis. — Improved starting device for gas and hydrocarbon engines.
11119. Lazar, Banki, & Csonka.— A new or improved mixing chamber for
petroleum and similar engines.
11261. Hamilton. — Improvements in oil engines.
11369. Weisman & Holroyd (amended). — Improvements in hydrocarbon
motors.
11526. Redfern (Nordenfelt £ Christophe).— An improved explosion en-
gine, also adapted to be driven by steam.
11593. Haddan (Pons y Curet). — Improvements in or relating to the con-
struction of pistons and their packings.
11726. Lamena. — A vapour spring, and improvements in connection with
the utilisation of the same.
11802. Dawson. — Improvements in gas engines.
11804. Ganswindt. — Improvements in mechanism for producing rotatory
motion from reciprocating motion.
11997. Fielding. — Improvements in explosive engines.
12520. Ewins. — A piston for engines.
12820. Tyler £ De Vesian. — Improvements in apparatus for mixing and
burning inflammable and explosive gases and vapours.
12840. Terry. — Improvements in apparatus for cooling circulating water in
gas and oil and other engines working by explosion, &c.
12917. Boult (Lausmann). — Improvements in or relating to reversing gear
for steam and other motors.
13298. Griffin. — Improvements in gas and oil motor engines.
J3333' Marks (Hirsch). — Improvements in gas engines.
13524. Vermersch.— Improvements in gas engines.
13546. Burt. — Improvements in apparatus or arrangements for transmitting
and controlling the power of gas or vapour or other motors.
13825. Arschauloff.— Improvements in caloric engines.
13996. Thompson (De Palacios & Goetjes).— Improvements in the art of
aerostation and apparatus therefor.
14002. Holt. — Improvements in gas motor cars.
14476. Bryant. — A new or improved vapour or gas motor engine.
15061. Schumacher, Pickering, Whittam, & Platts. — Improvements in or
relating to hydraulic and other engines.
15109. Schimming. — Improvements in or relating to gas and similar motors.
15152. Faure. — Improvements in the propulsion and construction of veloci-
pedes and other vehicles.
15272. Weyman. — Improvements in oil or hydrocarbon engines.
15721. W. D. & S. Priestman. — Improvements in hydrocarbon engines.
16230. Saurer-Hauser.— Improvements in heating and igniting devices for
gas engines.
17233. Knight. — Improvements in oil or hydrocarbon engines.
17308. Roots. — Improvements in internal combustion engines.
536 The Gas Engine
NO.
17549. Maccallum. — Improvements in internal combustion engines.
18443. Terry. — Improvements relating to the use of liquid fuel, and appa-
ratus for that purpose.
18452. Bedson & Hamilton. — Improvements applicable to oil engines.
19894. Harris. — Improvements in high-speed gas engines.
20123. Shillito (The Leipziger Dampfmaschinen- und Motoren-Fabrik). — An
improved gas and petroleum motor.
20192. Grove & Hogg. — Improvements in hydrocarbon engines.
20538. Norris & Henty. — Improvements in hot air engines.
21032. Duke. — Improvements in the means for automatically lighting gas.
2^829. Abel (The Gas-Motoren-Fabrik Deutz). — Improved method of and
apparatus for working gas or oil motor engines operating with slow
combustion.
22852. Armstrong. — Hand starting gear for gas, oil, and other internal com-
bustion engines.
22891. Turner. — Disengaging starting handle for gas and oil engines and
other motors that are not self-starting.
22946. Clerk & Lanchester. — Improvements in gas and like engines.
23028. Robinson. — Improvements in gas and vapour engines.
23802. Pollock & Whyte. — Improvements in oil engines.
24089. Marks (Hirsch). — Improvements in gas engines.
24133. Heys (Letombe). — Improvements in gas and similar engines.
24239. Withers. — An improved gas engine.
24898. Hawkins. — An improved explosive for producing motive power, and
apparatus to be used in connection therewith
24949. Lindley. — Improvements in and connected with fluid-pressure motors.
25275. I. & T. W. Cordingley. — Improvements in apparatus for igniting
the gases in gas engines and the like.
25334. Goddard. — Improvements in threshing machines.
1895.
347. Humphrey. — Improvements in gas or oil motor engines.
546. Niemczik. — Ignition- and gas-generating-body for explosive engines
rendered incandescent by an electric current.
644. Pinkney. — Improvements in internal combustion engines.
749. Karavodin. — Improvements in fluid-pressure heat engines.
946. Marks (Hirsch). — Improvements in gas engines.
973. Wane & Horsey. — Improved arrangement of appliances connected
with internal combustion engines.
1046. Lones. — Improvements in gas steam and compressed-air engines.
1071. Boult (Karger). — Improvements in or relating to the cylinders of
heat engines.
1310. Hailing & Lindahl. — Improvements in or relating to apparatus for
controlling the valves of engines.
Appendix II 537
NO.
1580. Millet. — Improvements in velocipedes.
1623. Piers. — Improvements in connection with motive power engines for
driving tramway cars and other vehicles.
1884. Serret. — Improvements in apparatus for diminishing the noise of
gases escaping from the exhaust of gas engines and the like.
1922. Niemczik. — Arrangement for starting gas and petroleum engines.
2327. Clarke. — Improvements in gas and oil motor valve motion.
2550. Crastin. — Improvements in or applicable to gas engines.
2565. Ferranti. — Improvements in steam, hot-air, and other engines.
2594. Pennink. — A new or improved high and low pressure gas generator.
2638. James. — Improvements in or appertaining to gas and oil engines.
2890. Clerk. — Improvements in pneumatic-pressure power hammers.
3357. Stanley. — Improvements in and relating to explosion engines.
3638. Crossley. — Improvements in internal combustion oil engines.
3783. Warner & Rackham. — Improvements in gas motor engines.
3806. Collis. — Improvements in oil, gas, or vapour engines.
3923. Wallmann. — Improvements in petroleum and gas motors.
4116. J. P. & H. G. Binns. — Improvements in gas and oil engines.
4243. Diesel. — Improvements in regulating fuel supply for slow combustion
motors, and apparatus for that purpose.
4604. Furneaux & Butler. — Improvements in or relating to apparatus for
starting hydrocarbon and like motor engines.
4786. Tangyes Limited & Robson. — Improvements in internal combustion
engines.
4972. Kolbe. — Improvements in fluid-pressure heat engines.
5373. Johnson (Tower). — Improvements in vehicle motors.
6151. Wildt. — An improved gas engine.
6383. Southall. — Improvements in gas and oil motor engines.
6523. The Brayton Petroleum Motor Co. Ld. & Townsend. — Improve-
ments in governing apparatus for engines.
6800. Mackenzie (Crouan). — Improvements in gas engines and the like.
6972. Donaldson. — Improvements in gas motors.
6974. Southwell. — Improvements in explosion engines.
7197. Weatherley.— Improvements in petroleum engines.
7747. Weatherley. — Improvements in petroleum engines.
8120. Merichenski & Moffat. — A new or improved apparatus for the pro-
duction of gas from oil.
8197. Turner & Harding. — A combined exhaust silencer and circulating
pump for gas engines.
8355. Klunzinger. — Ignition apparatus for gas and oil engines.
-88 1 5. Kolbe. — An improved method and means for transmitting or convert-
ing power or movement, &c.
8817. Kolbe. Improvements in or connected with fluid-pressure heat
engines.
538 The Gas Engine
NO.
9038. Melhuish. — Improvements in and connected with internal combustion
engines.
9188. Fraser. — System or process of heat regeneration and gas manufacture
for internal combustion engines.
9922. Berrenberg & Krauss. — Improvements in wheel motors for cycles and
other similar vehicles.
9964. Mex. — Improvements in and relating to petroleum motors.
10245. Williams.— -Improvements in blow-lamps.
10621. Pool. — Improvements in oil engines.
10710. Bell & Clerk. — Improvements in hydrocarbon motors.
10758. Abel (The Gas-Motoren-Fabrik Deutz).— A combined locomotive gas
engine with car.
11282. Howard & Bousfield. — Improvements in or connected with explosion
engines.
11400. Duryea. — Improvements in or relating to motor vehicles.
11493. Green. — Improvements in gas motor engines.
11709. Hewitt. — Improvements in steam, air, and gas rotary engines, and in
exhaust and compression pumps.
11925. Melhuish & Beaumont. — An improved high speed gas or hydro-
carbon engine. .
11955. Atkinson. — Improvements in internal combustion engines.
12095. Holt. — Improvements in valve gear for gas or oil motor engines.
12097. Dawson. — Improvements in oil engines.
12131. Pennink.— Improvements in or relating to high and low pressure gas
generators.
12287. Bray ton Petroleum Motor Co. Ld. & Withers.— Improvements in
petroleum and like engines.
12306. Diesel. — Improvements in direct combustion motor engines working
wdth multiple compression of the air required for combustion.
12409. Macdonald. — Improvements in motors, especially applicable to
tramways.
13047. Compagnon & Guibert.— Improvements in gas or petroleum motors.
13675. Lorenz. — Improvements in and relating to upright or vertical petro-
leum motors.
13975. Spiel. — An improved combined vaporiser and -igniter for oil motors.
14009. Spiel. — Improvements in and connected with the vaporising and
igniting devices of gas, petroleum, and similar motors.
14076. Durand. — Improvements in and connected with the inlet valves of
petroleum-motors.
14242. Ladd. — Improvements relating to explosion engines and to gas
generators to be used in connection therewith.
14361. Lorenz. — Improvements in and relating to hydrocarbon engines
working in a four-stroke cycle.
14385. Durr. — Improvements in gas and oil engines.
Appendix II 539
NO.
15045. Lanchester. — Improvements in gas and oil motor engines.
15310. A. & F. Shuttleworth & Deed. — Improved means for igniting the
combustible charges in gas, oil, and like engines.
15411. HinchlifTe. — Improvements in and connected with vaporisers of oil
and other similar engines.
15514. Day. — Improvements in oil engines.
15694. Clubbe & Southey. — Improvements in locomotive carriages for
common roads.
16068. Smith. — Improvements in connection with the propulsion of road or
other vehicles.
16079. Briggs. — Improvements in gas and oil engines or motors.
16096. Grist. — Improvements in apparatus for vaporising hydrocarbons or
other volatile liquids, and mixing the vapour with air for use in
motors.
16157. Clubbe £ Southey. — Improvements in internal combustion engines.
16362. Roger. — Improvements in self-propelling vehicles.
16556. Gass. — Improvements in gas engines.
16609. Campbell. — Improvements in gas and oil motor engines.
16703. Weatherhogg. — Improvements in petroleum and similar engines.
16891. White & Middleton. — Improvements in and relating to gas engines.
17282. Prince. — Improvements in means for propelling vehicles by internal
combustion motors.
17315. Duncan, Suberbie, & Michaux. — Improvements in petroleum
motors adapted for propelling vehicles and for other purposes.
17560. Hoyle. — A new furnace-gas or heat motor.
18070. Norris & Henty. — Improvements in valve gears for gas, oil, or other
engines.
18379. Johnston. — Improvements in gas and petroleum engines.
18706. R. D., W. D., & H. C. Cundall. — Improvements in oil motor
engines.
18794. Turnock. — Inprovements in and connected with means for supplying
and utilising compressed air for motive power and other purposes.
18908. Lanchester. — Improvements in gas and oil motor engines.
18995. Southall. — Improvements in operating the valves of gas and oil
engines.
19142. Grove. — Improvements in oil or gas engines.
19162. Bethell.— An improved plough.
19267. Gans. — An improved lighting apparatus for explosive gas mixtures,
more especially for motors.
19391. Gumming. —Improvements in refrigerating machinery.
19568. Briinler. — Improvements in explosion engines.
19700. Gautier £ Wehrle. — Improvements in rotary engines and pumps.
19734. De Dion £ Bouton. — Improved means or apparatus for electrically
igniting and governing petroleum and other like motors.
54-O The Gas Engine
NO.
I9735- De Dion & Bouton. — Improvements in motors worked by explosive
mixtures.
19744. Barker — Improvements in or connected with vaporisers for oil
engines.
19980. Delahaye. — Improvements in motors worked by petroleum or other
liquid hydrocarbon.
20189. Johnston. — Regulating or adjusting the transmission of power and
speed of prime movers.
20305. Kane.— Improvements in gas and like engines, and in the method of
mixing and volatilising the gases in the same.
20411. Erben. — Improvements relating to mechanically propelled vehicles.
20666. Nunn. —A gas or oil motor mowing machine.
20703. Lister. — Improvements in gas and like motor engines.
20705. Bickerton. — Improvements in gas engines.
20914. Boult (La Societe Fra^aise des Cycles Gladiator). — Improvements
in or relating to motor vehicles.
21315. Allen & Barker. — Improvements in oil and gas engines.
21484. Enger. — An improved method of and apparatus for governing or
regulating motors.
21521. Pinckney. — Improvements in and connected with generating steam
and furnace gases, and for utilising the same for motive purposes.
21568. Conrad. — Improvements in or relating to explosion engines.
21574. Fessard. — Improvements in gas and oil engines.
21594. Green. — Improvements in means for starting explosion engines.
21774. Magee.— Improvements in and relating to gas engines.
21912. White. — Improvements in and connected with governors for gas and
oil engines.
21993. Washburn. — Improvements in combined motive power and electric
generating and storing apparatus for the propulsion of movable
conveyances and analogous power purposes.
22161. Prestwick & The Protector Lamp and Lighting Co., Ld. — Im-
provements in velocipedes and other vehicles.
22347. Clubbe & Southey. — Improvements in engines for the propulsion of
road carriages.
22402. De Dion & Bouton. — Improvements in motors worked by explosive
mixtures.
22523. Heeley, Graves, & Coates. — An apparatus for the immediate stoppage
of gas or steam engines from any room of the works or factory.
22690. Marks. — Improvements in gas, oil, and like engines.
22793. Rowbotham. — Improvements in and relating to motor engines, for
vehicles and launch propulsion in particular.
23113. Wise (Buckeye Manufacturing Co.). — Improvements in gas engines.
23412. Tenting. — Improvements in self-propelling or horseless vehicles, and
in petroleum motors employed for driving the same.
Appendix II 541
NO.
23417. De Sales. — Improvements in gas and other like engines.
23706. Boult (La Societe Fran9aise des Cycles Gladiator). — Improvements
in or relating to motor vehicles.
23740. Thompson & Webb. — A rotary gas or oil motor for driving tricyles
or other light vehicles.
23771. Pennington.— Improvements in self-propelling road vehicles.
23879. Warsop. — Improvements in oil engines and the like.
24101. Cooper. — Improvements in driving gear for locomotive carriages.
24235. Brindley, Naylor, & Wilson. — Improvements in or in and relating to
self-propelled road vehicles.
24411. Wordsworth, Wiseman, & Holroyd. — Improvements in motors
worked by hydrocarbon or other gases, and in means for con-
trolling same.
24792. Rogers. — Improvements in gas and explosive vapour engines.
25024. Livingston. — Improvement in engine stops.
25050. Pennington. — Improvements in and relating to aerial vessels and to
methods of propelling and controlling the same.
1896.
313. Gautier. — Improvements in petroleum motors and the like.
624. New. — Improvements in gas and oil engines.
731. Hamilton & Rollason. — Improvements in self-propelled vehicles.
786. Smith. — Improvements in gas and oil engines, part of the same being
applicable to steam engines and the like.
795. Abel (The Gas-Motoren-Fabrik Deutz). — Means for cooling the inlet
vavle of gas and oil motor engines.
884. Capitaine. — An improved mode and mechanism for regulation of the
temperature of the combustion chamber and vaporiser in petro-
leum motors.
996. Pennington. — Improvements in explosion engines.
1095. Beverley. — Improvements in hydrocarbon and petroleum engines.
1327. Dougill & Marks. — Improvements in governing-apparatus for engines
in which gas or vapour and air are used.
1404. Maxim. — Improvements in the conversion of heat energy into mechani-
cal energy, and in apparatus therefor.
1789. Sohnlein.— Improvements in oil, gas, and other motive power
engines.
2024. Crowden. — Improvements in or relating to explosion motors.
2113. Howard & Bousfield. — Improvements in gear for transmitting rotary
motion.
2138. Roots. — Improvements in internal combustion engines.
2171. Lewis. — Improvements in gas and other such like engine cylinders,
and in the mode and means for keeping such cylinders from be-
coming unduly hot.
542 The Gas Engine
NO.
2290. Lane. — Improvements in gas or petroleum engines, especially applic-
able to such engines when used for propulsion of vehicles, &c.
2394. Sturmey. — Improvements in or relating to velocipedes and other
vehicles, and self-contained motors therefor.
2436. Maxim. — Improvements in process and in means or apparatus for pro-
ducing motive power from combustible liquids, gases or vapours.
2753. Bamford £ Wadsworth. — Improvements in gas engines, in part
applicable to oil and similar engines.
2874. Marchant. — Pumps driven by vaporised oil motors.
2895. Crossley & Atkinson.— Improvements in igniting apparatus for inter-
nal combustion motors.
3062. Taylor. — Improvements in oil vaporisers.
3217. Abel (The Gas-Motoren-Fabrik Deutz).— -Improvements in upright
gas and oil motor engines.
3331. Reynolds &. Astley. — An improved automatic feed for supplying oil
or other liquids in regulated quantities for burning, lubricating,
or other purposes.
3381. Baker. — Improvements in or relating to explosion engines.
3503. A. & F. Shuttleworth & Deed. — Improvements in the igniting
arrangements of gas and hydrocarbon engines.
3696. W. B. & C. S. Brough. — Improvements in motive power engines
actuated by the explosive force of gases or vapours.
3798. Carpenter £ Allen. — Improvements in cultivators.
4067. Burne. — Improvements in motive power engines actuated by the
explosive force of gases or vapours.
4069. Clubbe & Southey. — An electric vaporiser for oil engines.
4153. Bromhead (Niel). — A double-acting gas engine.
4184. Rowbotham. — Improvements in gas and like engines, and in the
method of mixing and volatilising the gases in the same.
4245. Holt. — Improvements in gas or oil traction cars.
4492. Martineau. — Improvements in internal combustion engines.
4618. Mallet. — Improvements in petroleum and like motors.
4634. Crow. — Improvements in gas, petroleum, and other internal com-
bustion engines.
4766. Alston. — Improvements in and relating to compound gas engines.
4924. Simpson. — Improvements in gas and other hydrocarbon engines.
4938. Wenham. — Improvements in engines worked by combustible gases or
vapours, more especially intended for propelling vehicles.
5277. Donaldson. — Improvements in the gas control of an explosive gas
motor.
5598. Thompson. — Improvements in or relating to apparatus applicable for
braking and starting oil, gas, and other engines, also machinery,
tramcars, and other vehicles.
5814. Lanchester. — Improvements in gas and oil motors.
Appendix II 543
NO.
5860. Ledin. — Improvements in and relating to motors actuated by pro-
ducts of combustion mixed with steam.
•6067. Briggs. — Improvements in or connected with gas and oil engines or
motors and carriages propelled thereby.
•6073. Cook. — Improvements in and connected with means for generating
combustion products under pressure, and utilising the same for
operating heat engines and for propelling ships.
6378. Adorjan. — Improved valve motion and engine for highly superheated
steam or gas.
-6573. Dowsing & Keating.— An improvement in engines worked by gas or
combustible vapour.
6590. Hall. — Improvements in or relating to variable speed apparatus for
transmitting power.
•6718. Prince. — Improvements in and connected with internal combustion
motors.
•6738. W. D. & S. Priestman & Richardson. — Improved means applicable
for use in igniting the working charge in hydrocarburetted-air
engines.
•6740. Ibbett. — Improvements in gas, oil, or hydrocarbon vapour engines.
•6834. Gascoine & Courtois. — Improvements in horseless carriages.
6872. Pinkert. — New or improved motor for propelling and manoeuvring
vessels.
6915. Hilderbrand. — Improvements in or relating to motor cycles and
the like
•6933. Hornsby, Edwards, Roberts, & Young. — Improvements in explosion
engines.
6974. J. S., R. D., W. D., & H. C. Cundall.— Improvements in motor
engines operated by oil, gas, and other explosive matter.
7036. Duryea. — Improvements in or relating to gas and like motors.
7147. Auriol. — Improvements in gas and oil engines.
7250. Bousfield (La Societe des Precedes Desgoffe et de Georges). — Im-
provements in centrifugal pumps and motors.
7454. Berrenberg. — Improvements in the construction of motor engines, and
their application in the propulsion of autocars and road -carriages.
7543. Best. — Improvements in petroleum engines.
7549. Pennington.— Improvements in starting devices for motors.
7566. Riib. — Improvements in motor-driven velocipedes.
7603. Lanchester. — Improvements in gas and other motive power engines.
7609. Tavernier. — A new or improved motor actuated by explosions.
7822. Bickerton. — Improvements in oil engines.
7825. Clark.— Improvements in apparatus for compressing air.
7940. Simms (May bach). — Improvements in or in connection with petro-
leum burners for heating purposes.
8089. Seek. — Improved outlet-valve motion for gas and oil engines.
544
The Gas Engine
NO.
8255. Dale. — Improvements in mechanical motors driven by steam, com-
pressed air, mixtures of gas and air, petroleum and air, or other
explosive mixtures.
8306. Bollee. — Improvements in or relating to self-propelled vehicles.
8359. MacDonald. — Improvements in and connected with motor power
apparatus for propelling vehicles and boats.
8813. Bickerton. — Improvements in gas and oil engines.
8918. Young (Gardner). — Improvements in explosion engines.
9052. Loyal. — Improvements in petroleum and like motors.
9092. Tubb & Mondey. — Improvements in and relating to oil, gas, and
vapour engines.
9143. Carse.— Improvements relating to motor-driven vehicles.
9199. McGhee.— Improvements in the valves and valve gear of gas or
internal combustion motor engines.
9256. Fetter. — Improvements in or relating to the arrangements of the air
and exhaust valves of internal combustion engines.
9259. Boult (Landry & Beyroux). — Improvements in or relating to explo-
sion engines.
9336. De Dion & Bouton. — Improvements in explosion motors.
9337. De Dion & Bouton. — Improvements in the valvular arrangement of
petroleum and like engines.
9526. Maxim. — Improvements in and relating to oil and gas engines.
9571. De Chasseloup-Laubat. — Improvements in steam, gas, and other
engines.
9732. De Dion £ Bouton. — Improvement in or connected with explosion
motors.
9770. Hockett. — Gas engine.
9982. Lane. — Improvements in gas, oil, or other internal combustion
. . engines or motors.
10018. Lane. — Improvements in or connected with motive power apparatus
consuming liquid fuel, such as petroleum and heavy oils.
10141. Mors. — Improvements in and relating to self-propelled vehicles.
10164. Duncan.— Improvements in and relating to the driving of light vehicles.
10307. J. P. & H. G. Binns. — Improvements in gas and oil engines.
IO399- Bennett & Thomas.— Improvements in gas, oil, and spirit engines.
10424. Simms. — Improvements in cooling the surfaces of the cylinders of
explosively driven engines by means of air.
10690. Tangyes Ld. & Robson. — New or improved mechanism for revers-
ing and stopping oil, gas, or other motors driven by machinery or
apparatus.
11058. Clubbe, Southey, & the Electric Motive Power Co., Ld. — Improve-
ments in motor cars or autocars, applicable also to launches.
11078. Peugeot. — Improvements in oil engines.
11088. Gans. — Improvements relating to igniters for the motors of auto-
motive vehicles and feed vessels therefor.
Appendix II
545
Bomborn. — Improvements in vaporisers for petroleum engines.
Day. — Improvements in and connected with gas and oil engines.
P'aure. — Improvements in or connected with motor-driven road
vehicles. ,
Wiseman & Holroyd. — Improvements in hydrocarbon motors.
Hay ward. — Improvements in rotary engines.
Barker.— Improvements in fog or audible signalling apparatus for
lighthouses and the like.
11475. Longuemare. — Improvements in burners for petroleum and other
vapours.
11481. Tomlinson. — Improvements in the driving of machinery, vehicles,
boats, and the like, by electro-motors or other high-speed motors.
11491. Holden. — Improvements in the construction of internal combustion
engines for propelling carriages, cycles, and boats.
11506. Magee. — Improvements in and connected with railway vehicles and
road vehicles driven by means of oil motors.
1 1 549. Hamerschlag. — -Improvements in igniting devices for gas and petro-
leum engines.
11573. Haddan (De Coninck). — Improvements in and relating to auto-
motive vehicles.
11914. Lutzmann. — Improvements in and connected with motor-propelled
vehicles.
11992. Polke. — Improved cam mechanism.
12003. Abel (The Gas-Motoren-Fabrik Deutz). — Appliance employed in
starting gas and oil motor engines.
12041. Smith. — Improvements in road motor cars and in machinery for the
same.
12274. Hunter. — Improvements in internal combustion motors for use in the
propulsion of automobile vehicles and water craft and for general
purposes.
12337. British Motor Syndicate, Ld. (Maybach) — Improvements in port-
able engines.
12446. J., S., F., & E. Carter. — Improvements in explosion engines.
12539. Paget. — Improvements in and connected with fly-wheels for motor-
cars.
12633. J. A. & W. Drake. — Improvements in oil or gas engines.
12758. Crouan. — Improvements in motive power engines driven by gas or
inflammable vapour.
12776. Hilderbrand. — An improved carburettor or gas-producer.
12805. Altham. — Improvements in oil engines.
12943. Rowbotham. — Improvements in gas-generating apparatus for expkv-
sion engines.
I3^33v Young (Gardner). — Improvements in and relating to igniters for ex-
plosion engines or motors.
N N
546 The Gas Engine
NO.
13864. Audin. — Improvements in gas or petroleum engines.
14212. Wood. — Improvements in explosion engines.
14213. Peugeot. — A new system of air carburettor.
I4375- W. & C. S. Gowlland. — Improvements in and connected with means
for the utilisation of acetylene gas in motors and ordnance, and for
producing explosions and for other purposes.
14446. W. & C. S. Gowlland. — Improvements in or relating to fluid-pressure
motors.
14639. Dowsing. — Improvements in apparatus or the production of electri-
city from the waste heat of gas, steam, or other heat engines.
14731. Wilson. — Improvements in the vaporising and igniting devices of
petroleum engines.
14756. Roots. — Improvements in or connected with oil engines for pro-
pelling carriages, boats, and the like.
14829. Rowbotham. — Improvements in vaporising arrangements for oil or
inflammable vapour engines.
14959. Merrit & Naismith. — Improvements in internal combustion engines.
15045. Baker. — Improvements in gas or vapour engines.
15127. Melhuish. — Improvements in and relating to the construction and
arrangement of gear for regulating or automatically controlling the
speed and power of internal combustion engines, &c.
15197. Keys (Heilmann). — Improvements in oil and gas engines.
15267. Stilwell. — Improvements in engines operated by gas, vapour, oil, or
the like.
15279. Rowbotham. — Improvements in vaporising apparatus for explosion
engines.
15752. Gowlland. — Improved method of obtaining motive power from
gaseous pressure, and apparatus therefor.
16067. Banks. — Improvements in oil motors, specially applicable to cycles.
I6277A. Pratis & Marengo. — The utilisation of hydrogen gas for the obtain-
ment of light, heat, and power.
16348. Gordon. — Improvements in ignition apparatus for explosive engines.
16366. G. G. & R. O. Blakey. — Improvements in gas and other explosive
engines.
16465. Bollee. — Improvements in or relating to motor or self-propelled road
vehicles.
16512. Singer. — Improvements in internal combustion or detonating engines.
16630. Bectz. — Improvements in rotary explosion engines or motors.
16660. Bennett & Thomas. — Improvements in oil and spirit engines.
16708. Hunt. — Improvements in regulating apparatus for gas motor engines.
16997. Lacasse. — New or improved horseless carriage.
17203 Gale & Thompson. — Improvements in methods and means for electric
regulation of power.
17221. Gautier & Wehrle. — Improvements in and relating to motor vehicles.
Appendix II 547
NO.
17448. Jahn. — Improved starting apparatus for gas engines and the like.
17573. Pennington.— Improvements in or relating to the ignition of the
charge in explosion, oil, and like engines.
17926. Reynolds.— An improved explosion motor for cycles, vehicles, and
vessels.
18051. Holt. — Improvements in gas or oil motor tramcars and similar
vehicles.
18194. Golby (Rumpf.). — Improvements in hydrocarbon motors.
18202. Huskisson. — Improvements in and relating to rotary turbine engines.
18294. Abel (The Gas-Motoren-Fabrik Deutz). — Method for starting gas and
oil motor engines with twin cylinders.
18304. Bromhead (Neil). — A double-acting or duplex oil engine.
18520. Dunkley. — Improvements in motor carriages.
18551. Clubbe, Southey, & the Electric Motive Power Co. Ld. — Im-
provements in and relating to the suspension or supporting of
engines on motor carriages.
18585. Arrol & Johnston. — Improvements in oil or gas motors for wheeled
vehicles and for general purposes.
18783. Austin. — Improvements in mechanically propelled road vehicles.
18829. Lanch ester. — Improvements in the igniting arrangements of gas and
oil motor engines.
18831. Stephens. — Improvements in oil engines for marine and vehicular
propulsion.
18988. Edwards (C. & J. Kiister). — Improvements in apparatus for equalis-
ing the pressure upon the crankpins of steam and other engines.
19061. Bergmann & Vollmer. — Improvements in or appertaining to autocars
and the like.
19136. Grelet. — An improved explosion motor.
19211. Prince, Smith & Monkhouse. — Improvements in internal com-
bustion motors.
19232. Smith. — Improved means for lessening vibration in reciprocating
engines and machines.
20428. Roger. — Improvements in gas and oil motors for autocars.
20449. Smith. — Improvements in lubricating the cylinders, pistons, and
valves of gas engines.
20655. Wilkinson. — Improvements in gas, oil, and like engines for autocars,
also applicable for other suitable purposes.
21136. Lister. — Improved oil or gas engine applicable for use in the pro-
pulsion of vehicles.
21274. Mundcn. — Improvements in motor vehicles.
21587. Faure. —Improvements in hot-air engines.
2I^75- Johnson. — Improvements in and connected with motor carriages.
21743. Martel. — Improvements in the construction of hydrocarburetted-air
engines, and in their application to tram and other road vehicles.
N N 2
548 The Gas Engine
NO.
21877. Hornsby & Sons, Ld. (Burton). — Speed regulating mechanism or
petroleum and other motors.
22064. Bayer. — Improvements in rotary engines.
22376. Southall. — Improvements in oil engines.
22527. Gibbon. — Improvements in explosion engines.
22935. Lanchester. — Improvements in gas and oil motor engines.
23005. Quentin. — Improvements in and relating to hydrocarbon vapour motors.
23110. Tangye & Johnson. — Anew or improved gas and oil or petroleum
engine.
23138. Lones. — An improved gas engine, convertible into an oil engine or
vice versa.
23142. Petavel. — Revolving cylinder oil or gas engine.
23270. Petreano. — Apparatus for vaporising hydrocarbons, applicable to
engines worked by gas, petroleum, alcohol, and the like.
23296. The Motive Power & Light Co. Ld. & Friend. — Improvements
in hydrocarbon motors.
23306. Auge. — Improvements in explosive engines.
23350. — Arrol & Johnston. —Improvements in apparatus for forming and
regulating the combination of oil with air for oil motors.
23462. Wisch. — Reversing-gear for explosion motors.
23492. Monin & Perot. — Improvements in and relating to gas and petroleum
motors.
23604. Roots & Venables. — Improvements in or connected with oil motors
for vehicles, cycles, boats, and the like.
23802. O'Brien (Triouleyre). — Improvements in autocars.
23860. Swiderski & Schwicker. — Self-heating vaporiser for mineral oil
motors.
24091. Dawes. — Improvements in internal combustion engines.
24144. Thompson (Pillon & Le Melle).— Improved balanced motor engine.
24311. Dawes. — Improvements in internal combustion engines.
24457. W. D. & S. Priestman. — Improvements in igniting devices for
hydrocarburetted-air engines.
24550. Gathmann. — Improvements in rotary gas and oil engines.
24656. Bickerton. — Improvements relating to the utilisation of waste gases
from gas engines for heating purposes.
24793. Crastin. — Improvements in or connected with apparatus for vapor-
ising oil.
24804. Ide. — Improvements in steam, gas, or other engines.
24805. Lanchester. — Improvements in the igniting arrangements of gas and
oil motor engines.
24858. Caldwell. — An improved governor, especially applicable to gas
engines and the like.
24881. Furneaux & Butler. — Improvements in explosion engines specially
suitable for propelling vehicles, boats, and other bodies.
Appendix II 549
NO.
24905. Nayler. — Improvements in vaporisers for oil motors.
24994. Oechelhaeuser. — Improvements in high-pressure gas engines.
25558. Arnold. — Improvements in the method and means for discharging the
vapour generated in the water jackets of gas and oil engines.
25642. Smith. — Improved apparatus for silencing the exhaust in gas or other
engines.
26233. Allen & Barker. — Improvements in oil and gas engines.
26261. Mewburn (Bates). — Improvements in and in connection with the
manufacture of combustible gas, including illuminating gas, and in
apparatus or plant for the purpose.
26292. Baines & Norris. — -Improvements in engine lubricators, in part applic-
able to oil-feeding appliances for oil engines.
26399. Read & Turner. — Improvements in gas and oil engines.
26638. Allsop. — Improvements in gas and petroleum engines and motors.
26879. Power. — Improvements in governing oil, gas, and vapour engines.
27184. Simpson. — Improvements in motor-driven vehicles.
27207. Pennington. — Improvements in the electric ignition of charges in
explosion engines.
27208. Pennington. — Improvements in means for suppressing the noise of
the exhaust from internal combustion engines.
27276. Middleton. — Improvements in motor wheels or mechanical tractors.
27408. James. — Improvements in engine 'exhausts.'
27535- Payne.— Improvements in hydrocarbon and other vapour motors.
27568. Johnson. — Improvements in oil and gas motors.
27602. Holden. — Improvements in the construction of internal combustion
engines in combination with cycles or carriages.
27603. Holden.— Improvements in the construction of internal combustion
engines in combination with cycles or carriages.
27979. Thomson. — Improvements in apparatus for deriving, controlling, and
regulating motive power from gas or oil engines for various pur-
poses.
28117. Lyon. — Improved means or apparatus for igniting explosive gases in
petroleum and other like motors.
28514. Tomlinson. — Improvements in and relating to internal combustion
and compressed-air engines.
28523. Dutton. — Improvements in oil, gas, and analogous motors.
28527. Mackenzie & Carling. — Improvements in gas or oil motor engines,
also applicable to steam or other fluid-pressure engines.
28583. Lepape. — A new or improved cooler for petroleum motors.
28648. Balzer & Humphrey. — Improvements in motors or engines.
28842. Culver. — Improvements in gas engines.
28867. Geisenhof. — An improved motor-van.
28892. Wood.— Improvements in valve gear for gas or oil engines.
28979. Roser & Mazurier. — Improvements in and relating to gas or petro-
leum and like motors.
55O The Gas Engine
NO.*
29067. Turner. — An improved silent condenser for gas arid like engines.
29578. Bryan. — Improvements in combined internal combustion and com-
pressed gas or air engines.
29610. Jones. — Improvements in and pertaining to motors adapted to be
worked by pressure of fluid, such as a combustible mixture of petro-
leum vapour, or gas with air, or analogous motive fluid.
29718. Hardingham (Webster).— Improvements in rotary engines, applicable
for use as motors, pumps, blowers, or the like.
29747. Higgins, Bessemer, & Nicholson. — Improvements relating to engines
or motors and to the application of the same for the propulsion of
vehicles.
29854. L'Homme. — Improvements in explosion engines or motors.
29858. Altmann. — Improved method and apparatus for burning liquid fuel.
30010. Potter. — Improvements in engines actuated by oil, petroleum, spirit,
or other gas-generating liquids.
30026. I. & T. W. Cordingley & Smith. — Improvements in oil motors.
30045. Toll. — Improvements in or relating to the valve mechanism of explo-
sion engines.
30075. Marsden. — Improvements in oil or liquid hydrocarbon motors.
30133. Askham. — Improved apparatus applicable to gas engines.
30162. Romer & Perkes. — Improvements in explosive gas motors.
l897.
95. Dagnall. — Improvements in internal combustion engines.
659. Riib. — Improvements relating to the igniting devices of the motors
of motor cycles.
679. Lister. — Improvements appertaining to oil engines.
736. M. H. C. & R. E. C. Shann.— Improvements in or relating to ex*
plosion engines.
746. Gautier & Wehrle. — Improvements in carburetting-apparatus.
878. Philippot. — An improved atomising device for petroleum and other
motors.
900. Winton. — Improvements in explosion engines.
913. Norgrove, Westwood, J. & J. C. Bates, Poultney, & R. H. Bates.
— Improvements in or relating to vaporisers for oil engines and
the like.
I on. Wimshurst. — Improvements in gas and explosive vapour engines.
1160. Lake (La Societe Fritscher & Houdry). — Improvements in gas and
petroleum engines.
1400. Dougill. — Improvements in or relating to motor engines worked by
gas or other combustible vapours.
1402. Hunter. — Improvements in gas or oil engines.
1475. Poron. — Improvements in motor engines and gear for autocars,,
Appendix II 551
NO.
1598. Winton. — Improvements in explosion engines.
1652. Conrad. — An apparatus for governing the valve gear of hydrocarbon
motors.
1694. Winton. — Improvements in explosion engines.
1695. Winton. — Improvements in explosion engines.
2095. Holt.— A regulator of the circulation of cooling water.
2123. Martindale. — Improvements in motors operated by fluid or gaseous
pressure.
2595. Ringelmann. — Improved means for exploding combustible mixtures,
and utilising the explosive force thereof for driving rotary
engines.
2666. Johnson. — Improvements in and connected with the generating and
transmission of power for driving tramway carriages and other
road vehicles and for other purposes.
2849. Stroh. — Starting device for oil engines.
3025. Maxim. — Improvements in cooling devices for gas, oil, and steam
and similar engines.
3370. Crossley. — Improvements in internal combustion motors.
3890. Auriol. — Improvements in gas engines.
4299. Paterson. — Improvements in and connected with petroleum and like
engines for motor cars and other purposes.
4528. Caley & Stephenson.— Improvements in gas, oil, and other ex-
plosion engines.
4556. Pennington.— Improvements in or relating to the cooling of cylinders
of explosion engines.
4580. Ollivier. — Improvements relating to explosion engines.
4605. Ball. — Improvements in and relating to oil and gas engines.
4610. Embleton. — Improvements in explosion motors.
4640. Vallee. — Autocar with special petroleum motor.
4879. Prentice. — Improvements in steam, gas, and other engines.
4888. Ollivier. — Improvements in gas, petroleum, or like motors.
4963. Hamilton.— Improvements in steam, gas, and air engines.
5147. Rolfe & Hornby. — Improvements in and connected with explosion
engines.
5522. Brewer (Nicolas). — Improvements in or connected with gas or
internal combustion motors.
5526. Clubbe, Southey, & The Electric Motive Power Co. Ld. — A firing
device for internal combustion engines.
5618. Bowden & Urquart. — Improvements in or connected with internal
combustion engines working with liquid hydrocarbon and air.
5736. Lees. — Improvements applicable to explosion engines.
5882. Roots & Verables. — Improvements in petrocars or motor vehicles.
6035. Dunsmore. — Improvements in and relating to gas and oil engines.
6645. Tournet. — Certain improvements in oil and gas engines.
552 The Gas Engine
NO.
6651. Hargreaves. — Improvements in or relating to internal combustion
engines.
6688. Myers. — Improvements connected with explosive vapour power
engines.
7074. Rowden. — Improvements in apparatus for igniting the compressed
charges in gas or oil motors.
7098. Reeve. — Improvements in and relating to gas or liquid fuel engines.
7333. Le Brun. — Improvements in gas, petroleum, or like motors.
7526. Sundberg. — Improvements in regulating devices for gas and petro-
leum engines.
7770. Baines & Norris. — Improvements in oil engines.
7785. Banki & Csonka. — Improvements in automatic igniting apparatus for
gas and petroleum motors.
7969. Longuemare. — Improvements in carburettors for explosion engines.
7979. Martindale. — Improvements in rotary engines.
8056. Piitsch.— Improvements in or relating to gas engines.
8064. Marks (Bouvier).— Improvements in vaporisers for oil motors.
8100. Shann. — Improvements in or relating to internal explosion engines.
8318. Pinkney. — Improvements in oil engines.
8471. Royer. — Improved means for cooling the water or condensing the
steam from the motors of motor-cars.
8529. Dougill & Marks. — Improvements in gas, oil, and like engines.
8547. Thornton & Pollard. — Improvements in motors worked with heated
compressed air, in parts applicable to internal combustion engines.
8822. Wimshurst. — An improvement in gas or oil engines.
9002. Erie. — Improvements in motor road vehicles.
9098. Sciitz & Heydemeyer. — Improvements in or relating to apparatus foi
starting gas engines or the like.
9389. Baker. — Improvements in gas engines.
9463. Klaus. — Improvements in motor or self-propelled vehicles.
9722. Roots & Venables.— Improvements in and connected with oil motors
for vehicles and propelling generally.
9784. Grivel. — Improvements in and relating to carburetting apparatus,
particularly applicable to petroleum engines, oil engines, and the
like.
9907. Peugeot. — An improvement in oil engines.
9929. Buck & Torrey. — Improvements in apparatus for carburetting air.
9963. Grivel. — Improvements in carburetting air or internal combustion
engines, particularly adapted for the propulsion of motor cars and
other vehicles.
10005. Fritscher & Houdry. — Improvements in gas or hydrocarbon motors.
10097. Henroid-Schweizer. — Improvements in internal combustion engines.
10261. Boult (Lefebvre). — Improvements in or relating to apparatus for
carburetting air.
Appendix II 553
NO.
10519. Johnson. — Improvement in and connected with oil and other ex-
plosion motors for the purpose of reducing the smell and visible
vapour of or from the exhaust.
10620. Maxim. — Improvements in aerial or flying machines.
11015. Marks (Chaudun). — Improvements in rotary motors.
11334. Vaughan-Sherrin. — Improvements in electric ignition devices for
gas engines and other gaseous explosive mixture engines.
11414. Baker & Offen. — Improvements in gear for converting reciprocating
motion into rotary in engines and other machines.
11520. Mitchell. — Improvements in rotary engines.
11547. Casley & Woodman. — Improvements in hydrocarbon motors.
11619. Pilcher.— Improvements in and connected with engines actuated by
mixed products of combustion and steam.
11710. Boult (La Societe Anonyme d'Automobilisme et de Cyclisme). —
Improvements in or relating to oil and similar motors.
1 1 80 1. Fielding. — An improved vaporising and igniting device for gas and
oil motor engines.
11930. Esteve.— Improved mineral oil engine.
11951. Lamy & Richard. — Improvements in or relating to internal com-
bustion engines or motors.
12050. Fairhurst. — Improvements in motive power engines actuated by the
explosive force of gases or vapours.
12117. Pool. — Improvements in explosion engines.
12199. Johnson. — Improvements in and connected with fluid-pressure
apparatus for generating, storing, and transmitting power.
12553. Rossel. — Improvements in petroleum and like motors.
12924. Thompson (Loutzky). — An improved four-stroke cycle motor for
bicycles and the like.
I2942A. Johnson. — Improvements in electrical igniting apparatus for explosion
engines and for other purposes.
12954. Simms. — Improvements in cooling the surfaces of the cylinders of
explosively driven engines.
13092. Allsop. — Starting gas and petroleum engines and motors.
13161. Calloch. — -Improvements in internal combustion engines.
13325. Letombe. — Improvements in and relating to gas engines.
13517. Westinghouse & Ruud. — Improvements in gas engines.
13721. Straker, Caird, & Rayner. — Improvements in oil motor engines.
13734. Lake (La Societe Main Giusti & Co.) — An improved explosion
engine, more especially applicable to the propulsion of vehicles.
13988. Hunt. — Improvements in vaporisers and igniters for oil motor
engines, partly applicable to gas motor engines.
14165. Barnes. — Improvements in internal combustion engines using hydro-
carbon as fuel.
14298. Smith. — Gas motors with differential cyclinders.
554 The Gas Engine
NO.
J4397- Wattles.— Improvements in the generation and utilisation of hydrogen
gas and electricity for motive power, lighting and heating pur-
poses.
14455. Capel. — Improvements in gas engines.
14649. De la Croix. — Improvements in motor cycles.
14814. White (Brown). — An improved method of apparatus for generating
motive power by explosions.
14826. Hall. — Improvements in or relating to power-transmission apparatus.
15233. Duryea. — Improvements in hydrocarbon or gas engines.
15348. Simms. — Improvements in or connected with the exhaust valves of
explosion engines.
15354. Boult (Chaudun). — Improvements in or relating to rotary motors.
15411. Bosch. — Improved electVic igniter for gas engines.
15822. Crozet. — Improvements in or connected with cylinder and piston
motors.
15908. Katz.— Improvements in or relating to explosion motors.
15980. Sello, Schaefer & Lehmbeck. — Improvements in oil and gas engines.
15983. Uhlenhuth. — Improvements in internal combustion engines.
16074. Gallice. — Motor engine worked by explosive fluid mixtures.
16380. Ricci. — Improved mechanism for regulating the ignition point in oil
and other motors.
16399. Bracklow. — Improvements in or relating to gas and oil motors.
16411. Seunier. — An improved hydrocarbon motor.
16631. Russ. — Improvements in and relating to gas engines.
16705. Calloch. — A new or improved motor car.
16729. New. —Improvements in heavy-oil engines.
16943. Robinson & Molyneux. — Improvements in pistons.
16977. Jones. — Improvements in means for heating the ignition device for
gas, oil, or spirit engines.
17127. Petreano. — Improvements in and connected with gas and hydro-
carbon engines.
17204. Southall. — Improvements in gas and oil motor engines.
17317. Petreano & Bonnet. — Improvements in and connected with gas and
hydrocarbon engines.
17839. Hornsby & Edwards. — Improvements in or connected with explosion!
engines.
17842. Marconnet. — Improvements in or connected with apparatus for the
generation of gaseous fluid pressure.
18005. Thompson (Julien). — Improvements in and relating to apparatus for
producing gas suitable for heating, motive power, or lighting pur-
poses by the aid of volatile hydrocarbons.
18210. E., T. H., & L. Gardner. — Improvements in or relating to oil motors.
18531. Lawson. — Improvements in or relating to motors, especially suitable
for the propulsion of motor road vehicles. »
Appendix II 555
NO.
18546. Tomlinson. — Improvements in and relating to internal combustion
or explosive engines.
18804. Petreano. — Improvements in means for reversing gas and hydro-
carbon (petroleum) motors.
18940. Martini & Deimel. — Improvements in gas ignition apparatus.
19533. Hacklan (Heinle & Wegelin). — Improvements in gas motors.
19534. Haddan (Heinle & Wegelin). — Improvements in lubricating devices
for motor cycles.
19642. Dymond (Meyer). — Improved process for attaining a very high
ignition temperature in hydrocarbon engines.
19673. Hayot. — Improvements in gas turbines.
19910. Rowden. — Improvements in internal combustion engines.
19936. O'Donnel (De Bouilhac). — Improvements in and relating to motor
cars.
20116. Cail. — Improvements in or relating to internal combustion engines or
motors.
20135. Dymond (Diirr). — Improvements in hydrocarbon locomotives.
20236. J. F. & R. H. Shaw. — An improved method for supplying lubri-
cating oil in regular quantities for gas and oil engines and the like,
and for supplying in regular quantities combustible liquids for
driving purposes.
20269. Cordonnier. — New or improved rotary motor.
20389. Firman & Cave. — Improvements in explosion engines.
20455. Jensen (C. & A. White). — An electric igniter for internal combustion
engines.
20617. Martha. — Improvements in gas, petroleum or mineral-oil motors.
20761. Roots. — Improvements in internal combustion engines.
20801. Edmondson & Dawson. — Improvements in the method of and means
employed for starting internal combustion engines.
20880. Ironmonger.— Improvements in rotary engines actuated by steam or
other expansive gases.
21329. Button. — Improvements in oil, gas, and analogous motors
21738. Bomborn. — Improvements in fuel-feeding devices for petroleum
motors and similar combustion engines.
21833. Scott & Hawkins. — Improvements in and relating to the generation
of gas for motive power, illuminating, heating, and other purposes.
22065. Dymond. — Improvements in gas burners suitable for use in incan-
descent gas lighting and for other purposes.
22310. Pinkney. — Improvements in fluid-pressure heat motors.
22564. Fistie. — Improvements in gas engines.
22971. Leigh (Gosselin). — Improvements in motors driven by combustible
petroleum or any other suitable gas or vapour.
23357. Simpson. — Improvements in and connected with internal com-
bustion motors.
556 The Gas Engine
NO.
23361. Thompson (De Von). — Improvements in and relating to gas
engines.
23541. Cribbes & Ross.— A new or improved means of obviating or sup-
pressing the noise caused from the exhaust gases escaping from
gas or other engines, and apparatus connected therewith.
23582. W. D. & S. Priestman & Richardson.— Improvements in the work-
ing of internal combustion engines.
23622. Rowlingson (La Societe Diligeon et Cie). — Improved cooling
arrangement for internal combustion engines, specially applicable to
motor road vehicles.
24096. Weiss & Mietz. — Improvements in and connected with explosion
engines.
24432. Mason & Rixson. — Improved water regulator for heat in gas engine
water tanks.
24712. Doolittle (Still & Bengough). — Improvements in or pertaining to
motor apparatus suitable for propelling carriages, cycles, and other
road vehicles, or for light power purposes generally.
24861. E., T. H., & L. Gardner. — New or improved feed mechanism for
internal combustion engines.
25581. Crouan. — A lighting regulator for gas and petroleum motors, lighting
electrically.
25582. Crouan. — Electric lighter for gas and petroleum motors.
25856. Hesketh & Marcet.— New or improved means for generating gaseous
products of combustion under pressure, for operating engines or for
other purposes.
25987. Hamilton. — Improvements in gas and similar engines.
26898. Iden. — Improvements in spirit or light-oil motors for vehicles and
the like.
271 12. Crouan. — New system of regulator for gas and petroleum motors.
27301. Ravel. — Improvements in gas and like engines.
27315. Rowbotham.— Improvements in explosion engines.
28390. Boult (Rumpf). — Improvements in or relating to internal combustion
engines.
28821. Thompson (Irgens £ Brunn). — Improvements in and connected with
rotary motors.
28918. Turrell & Lawson. — Improvements in or relating to motor vehicles.
29074. Brillie. — Improvements in explosion motors.
29361. Kerridge. — Improvements in or relating to electric gas-lighting and
controlling devices.
29467. New. — Improvements in the ignition arrangements of explosion
engines.
29468. New. — Improvements in explosion engines.
29508. Huber.— Method and apparatus for utilising steam and combustion
gases at very high pressures as motive power.
Appendix II 557
NO.
29567. Boult (Dusaulx.) — Improvements in or relating to carburettors for
oil motors.
29593. Lloyd. — Improvements in and relating to explosion engines.
30106. Chauveau. — Apparatus for mixing the explosive charge of internal
combustion engines.
30182. Conrad. — Improvements in balancing devices for power engines
with thrust crank driving.
30266. Johnson. — Motor car.
558
NAME INDEX
TO
GAS AND OIL ENGINE PATENTS
1791-1897 INCLUSIVE
ABE
ABEL, C. D. (Beissel), 1882—3435
— (Daimler), 1879—3245; if"
343
(Langen & Otto), 1866—434;
1867—2245
. — (Daimler), 1874 — 414, 605 ;
1875—71
— — (Gas-Motoren-Fabrik Deutz),
1885—11933; 1886—5804; 1887—
847, 1189, 11503, 12187, 17188,
17896; 1888—688, 3020, 3095,
5724, 9602, 14349 ; 1889 — 5616,
18746, 20892 ; 1891—1903, 6717,
8469, 14519, 17724, 22847 ; 1892—
2728, 13204; 1893—735, 9181,
10274 ; 1894 — 408, 21829 ; 1895 —
10758 ; 1896—795, 3217, 12003,
18294
— (Otto), 1875—3615 ; 1876—
2081; 1878—1770; 1881— 60;
1883 — 1677
'(Spiel), 1881—4244
Adam, 1887—1266
Adams, 1891 — 741 ; 1892 — 6828 ;
1894—6364, 8041
Adorjan, 1896 — 6378
Aeugenheyster, 1888 — 13414
Ains worth, 1884—8960
Alexander, E.P., 1875 — 4342 ; 1879 —
3905
Allcock, 1881—565
Allen and another, 1895 — 2I3I5 >
1896—3798, 26233
Allison (McNett), 1889—12045
Allsop, 1897 — 13092, 26638
Alston, 1896 — 4766
AUG
Altham, 1896 — 12805
Altmann, 1888 — 8317 ; 1891 — 7157 ;
1892 — 21534 ; 1896 — 29858
Anderson, J., 1854 — 191 ; 1859 — 2767 ;
1866—3363 ; 1871—2326 ; 1882—
1754 ; 1887 — 15010
Anderson, 1888 — 14248, 17413 ; 1892
—12165
Andrew, 1883 — 1010, 3066, 4291 ;
1884—13221 ; 1885—5561 ; 1892—
17227, 20802, 20803
Angele, 1879—3905
Antisell & Bruce, 1875 — 2016
Arbos, J., 1862 — 3108
Archat, 1887 — 9111
Archibald, C. D., 1858—996
Aria, 1888—9342
Armstrong, 1894 — 22852
Arnold, 1896 — 25558
Arrol and another, 1896 — 18585,
2335°
Arschauloff, 1894 — 13825
Ashbury and others, 1882 — 5188
Asher, 1885 — 1424
Ash worth, 1891 — 18020
Askham, 1896—30133
Astley and another, 1896—3331
Atkinson, 1879 — 3213; 1881 — 4086;
1882—4378, 4388 ; 1884—3039,
16404; 1885—2712, 3785, 15243;
1886—3522 ; 1887 — 11911 ; 1889—
20482 ; 1892—2181, 2492 ; 1893—
16900, 23075; 1895—11955; 1896 —
2895
Audin, 1896—13864
Auge, 1896—23306
Name Indez
559
AUR
Auriol, 1896—7147; 1897—3890
Austin, 1896—18783
Aylesbury, 1880—3512
BABACCI, G. B., 1868—1393
Babbitt, 1867—3690
Babcock, 1886—478
Backeljau, 1884—11361 ; 1893—5256
Baines and another, 1896 — 26292 ;
1897-7770
Bainford, 1887—2236
Baker, 1896—3381, 15045 ; 1897—
Baldwin, 1882—4886 ; 1890—12678
Balestrins, H., 1855—1011
Ball, 1897—4605
Balzer and another, 1896—28648
Bamford and another, 1896—2753
Banki, 1889—6296
Banki and others, 1894—11119
Banki and another, 1897—7785
Banks, 1896—16067
Barber, J., 1791 — 1833
Barclay, 1891—6578; 1893—21908
Barker , 1 887 — 14027 ; 1 888 — 1 1 242 ;
1892-1879; 1895-19744; 1896—
11414
Barker and another, 1895—21315 ;
1896 — 26233
Barnes, 1897 — 14165
Barnett, W., 1838—7615
Barnett, 1889—18847
Baron, 1879 — 2
Barrett, 1891—8251
Barren, 1878—1170; 1891—19318
Barsanti & Matteucci, 1854 — 1072 ;
1857—1655 ; 1861 —3270
Bastin and others, 1894 — nioi
Bates, 1896-26261
Bates, J., J. C., and R. H., and
others, 1897 — 913
Bauer and another, 1881—1074
Baxter (Hoist), 1890—5005
Bayer, 1896—22064
Beaumont and another, 1895 — 11925
Bechfeld, 1887 — 14952
Beck, 1881—5534
Bectz, 1896 — 16630
Bedson and another, 1894—18452
Beechy, 1880—1653, 4270; 1881 —
2961 ; 1882 — 1318 ; 1885—3199 ;
1887—4160, 8818 ; 1890—10089
Beissel, 1882—3435
Bell, 1892-4347, 5972
Bell and another, 1895 — 10710
Bellamy, 1892—17277, 20802, 20803 I
l893— 4564. 6093. 7064. I5J-99 '•
1894—2656
BOU
Bellini & Carobbi, 1874—961
Benger, 1888—5204
Bengough and another, 1897—24712
Benier, 1881—1541, 4589; 1882 —
1868 ; 1884—16131 ; 1887—1262 ;
1894—1581
Bennett and another, 1882—6136 ;
1887—11567; 1896—10399, 16600
Benson (Rider), 1879 — 2191 ; 1880—
4250
Benz & Co., 1884— 9949 ; 1886—5789
Bergl, 1893—3292
Bergmann and. another, 1896—19061
Berk, 1894-6534
Bernadi, 1886—5665
Bernstein, 1884 — 1457
Berrenberg, 1896—7454
Berrenberg and another, 1895—9922
Bessemer, H., 1869—1435
Bessemer and others, 1896 — 29747
Best, 1892—24065 ; 1896—7543
Bethell, 1895—19162
Beugger, 1892 — 8538, 9439
Beverley, 1896 — 1095
Beyroux and another, 1896 — 9259
Bickerton, 1880—4643; 1881—1363;
1885—5519, 15845 ; 1887—17896 ;
1891 — 227, 297, 6090
— and another, 1882 — 2345; 1892 —
4078; 1893—14454; 1895-20705;
1896-8813, 7822, 24656
Bilbault, 1892 —5740
Binney, 1886—15319; 1888—10667;
14076 ; 1889—14868 ; 1890 — 7146 ;
15994; 1892-3909,22664
Binns, J. P. and H. G., 1895—4116 ;
1896—10307
— and others, 1894 — 5843
Bisschop, 1872—1594 ; 1882 — 579
Black, 1885—14574
Blakey, G. G. and R. O., 1896—
16366
Blanchard, F. B. , 1855—339
Bland, 1892-260
Blessing, 1888—1381
Blyth, 1887—516
Bobrownicki, 1866—181
Bollee, 1896-8306, 16465
Bolt, 1886—11576
Bolton, R. L., 1853—515
Bomborn, 1896 — 11209; l897 — 2I738
Bonnet and another, 1897—17317
Bosch, 1897—15411
Bosshardt (Huntington), 1891 — 9268
Boult (Larrivel & Aeugenheyster),
1888—13414
— (Berliner Maschinenbau Actien
Gesellschaft), 1891—383
560
The Gas Engine
BOU
BUT
Boult (Brauer & Windisch), 1893—
15900
— (Capitaine), 1888—15840, 15841,
15845, 15846
— (Charter), 1892—12183
— (Compagnie des Moteurs Niel),
1893—14546
— (Lausmann), 1894 — 12917
— (La Socie'te' Frar^aise des Cycles
Gladiator), 1895—20914, 23706
— (Karger), 1895—1071
— (Landry & Beyroux), 1896—9259
— (La Socie'te' Anonyme d'Automo-
bilisme et de Cyclisme), 1897—
11710
— Lefebvre), 1897—10261
— Chaudun), 1897—15354
— Dusaulx), 1897 — 29567
— Rumpf), 1897—28390
— (La Socie'te' des Moteurs Crebes-
sac), 1893 — 14891
Rotten), 1889—17024
Sharpneck), 1890 — 18645
Levasseur), 1891-9006
Boulton, M. P. W., 1864 — 1099, 1291,
1636,3044; 1865—501, 827, 1915,
1992; 1866-738; 1868—1988;
1876 — 2288, 3620, 3767 ; 1877 —
766 ; 1878 — 2278, 2525, 2609, 2707 ;
1879—495 '• 1881 — 1202, 1389, 3367 ;
1886 — 2653
Bouneville, H. A., 1867—1575
Bourne, J., 1868—1878, 3594 ; 1869 —
3705; 1870-1859
Bousfield and another, 1833—388 ;
1895 — 11282 ; 1896—2113
Bousfield and others, 1894 — moi
Bousfield (La Soci^te" des Process
Desgoffe et de Georges), 1896 —
7250
Bouton and another, 1895 — 19734,
22402 ; 1896—9337, 9732
Bouvier, 1897 — 8°64
Bowden and another, 1897 — 5618
Bower & Hollingshead, 1868—2808
Boys, 1886 — 10332
Bracklow, 1897 — 16399
Bradford, 1892 — 3156
Bradley, 1892 — 2862
Braham and another, 1882 — 2751
Brandon, A. H., 1869 — 3178
Brauer, 1893 — 15900
Brayton, 1874 — 2209; 1890 — 11062;
1894 — 6138
Brayton Petroleum Motor Co. Ld.
and another, 1895—6523, 12287
Breittmayer, 1880 — 3140 ; 1887 —
16257
Brewer (Nicolas), 1897 — 5522
Brice 1892 — 919
Bnggs, 1892—16365 ; 1895—16079 r
1896 — 6067
Brightmore, 1888 — 4057
Brillie", 1897 — 2074
Brindley (Naylor & Wilson), 1895 —
24235
Brine, 1884 — 12312 ; 1886 — 942
Brinn, Q. L., 1875 — 3274
Brinns, 1890 — 4362 ; 1892 — 13859
Briscall, 1883 — 5020
British Motor Syndicate Ld. (May-
bach), 1896 — 12337
Bromhead (Neil), 1896 — 4153,.
18304
Brooks, 1892—1246
Brooman, R. A., 1863 — 2098
Brough, W. B. & C. S., 1896—3696
Browett, 1884 — 14341 ; 1887 — 2520,
11345; i88G— 7547, 16057; 1889 —
18847
Brown, 1825 — 5150 ; 1826—5350 ;
1846 — 11072 ; 1882—1874 ; 1897 —
14814
Bruce & Antisell, 1875 — 2016
Briickert, 1893—9549
Briinler, 1886 — 2140 ; 1892 — 7047,
16379, 16380, 16381, 16382 ; 1893 —
16751, 16752, 21175 ; 1894 — 5680,
9780 ; 1895 — X9568
Brunn and another, 1897 — 28821
Brutton, 1889—6161
Bryan, 1896 — 29578
Bryant, 1984 — 14476
Brydges, 1881—3330
Buck and another, 1897 — 9929
Buckeye Manufacturing Co., 1895 —
23113
Bull, 1883 — 5113 ; 1887 — 10202 ;
1889—10634
Bullock, 1883 — 5085
Burgh, 1885 — 15194
Burne, 1896—4067
Burt, 1887 — 11678 ; 1888—3427 ;
1890 — 12690 ; 1891 — 19086, 22578 ;
1893—1277, 7466 ; 1894—13546
Burton, 1896 — 21877
Buss, 1875 — 1933
Butcher, 1879—2618, 4377 ; 1880—
474; 1881 — 3786; 1883—1835;
1884 — 5641
Butler, 1887—15598 ; 1888—1780,
1781 ; 1890—6900
— and others, 1889—9203; 1893 —
13282
Butter, 1894—7630
— and another, 1896—24881
Name Index
BUT
Butterworth, E., 1874—1652 ; 1884—
11086; 1886—207,7936, 12134
Buttress, 1885 — 1424
Byerley & Collins, 1838—7871
GAIL, 1897—20116
Caird and others, 1897 — 13721
Caldwell, 1896—24858
Caley and another, 1897 — 4528
Calloch, 1897 — 13161, 16705
Campbell, 1883—5951 ; 1885—6990 ;
1888-10748; 1891—4355; 1893—
15199, 24666; 1894—778; 1895 —
16609
Capel, 1897—14455
Capell, 1883—911
Capitaine, 1888 — 15840, 15841, 15845,
15846 ; 1891—8069 ; 1892 — 6872 ;
1894—5577; 1896-884
— (Benz & Co.), 1884 — 9949
- & Brimler, 1885—7500, 7581 ;
1886-2140
Carling, 1891 — no ; 1896 — 28527
Carpenter and another, 1896 — 3798
Carosis, A., 1853 — 1671
Carrobbi & Bellini, 1874—961
Carse, 1896 — 9143
Carter, J., S., F.( & E., 1894—9889 :
1896 —12446
Casley and another, 1897—11547
Casper (Tavernier), 1887—4757 ; 1888
— 5628 ; 1889 — 7069 ; 1890—1586
Casson, 1878 — 3774
Cattrall, 1885 — 11555
Cave and another,' 1897—20389
Charon, 1888 — 12399
Charter, 1887 — 1168, 12749; 1892 —
12183
Chasseloup-Laubat, 1896 — 9571
Chatter ton, 1892-6284
Chaudun, 1897 — 15354
Chauveau, 1897—30106
Chemin, 1888-9342
Christophe and another, 1894 — 11526
Clark, A. M. (Hurcourt), 1868-354
— (Lesnard), 1869-1748
— (Fell), 1879-1996
— (Kabath), 1883—999
— (Laurent), 1882—61^6
Clark, W., 1858-969
— (Merlanchon), 1863 — 1449
— (Bobrownicki), 1866—181
Clark (Economic Motor Co.), 1883—
4260; 1885—11294, 12483
— (Hopkins), 1884—11837
Clark/ M. E., 1896-7825
Clarke, T. A. W., 1895—2327
CRO
Clayton, 1878—2037 ; 1879—3140 ;
1880—4075; 1882—2202; 1884 —
2854
Clerk, D., 1877-252; 1878—3045;
1879-2424; 1881—1089; 1882—
4948 ; 1883—4046 ; 1886—12912 ~
1889—8805 ; 1891 — 12413, 16404,.
18788 ; 1892—5445, 11936, 13117 ;
1895—2890
Clerk and another, 1894—22946;
1895 — 10710
Clerk and others, 1881—3536
Cliff and another, 1883—638
Clubbe and another, 1895—15694,
16157, 22347 ; 1896—4069
Clubbe and others, 1896 — 11058,
18551 ; 1897-5526
Coates, 1890—6910 ; 1891—18276
Coates and others, 1895—22523
Cobham and another, 1884—3495
Cock, 1892—18513
Coffey, 1891-3350
Cohade, H. F., 1860-1585
Collins and Byerley, 1838 — 7871
Collis, 1895—3806
Colton (Hartig), 1885—9801
Compagnon and another, 1895—
T3°47
Connelly, 1890—5621 ; 1891 — 14002
Conrad, 1895 — 21568; 1897—1652,
30182
Cook, 1896 — 6073
Cooke, 1883—326
Cooper, 1891—4771 ; 1895—24101
Cordenons, 1889-6748
Cordingley, J. & T. W., 1894—
25275 ; 1896—30026
Cordonnier, 1897—20269
Cormack, W. , 1846 — 11245
Courtney (Brunler), 1892-7047
Courtois and another, 1896 — 6834
Cousins and another, 1879 — 4101
Covert, 1889—12472, 20249; I89r
993.1
Crastin, 1895-2550; 1896—24793
Crebassac, 1893 —14891
Cribbes and another, 1897-23541
Crist, 1889 — 20249
Cropper, 1878—3444
Crossley, 1876—132 ; 1880—4297 ;
1881—2227; 1882—4489; 1883 —
1722, 3079; 1884-4777, H578;
1885-8134; 1886 — 11285; 1887 —
5833; 1888—1705, 3756, 4624;
i895—3638; 1897-3370
— and another, 1878—5113; 1879 —
1912, 4499; 1880—3411; 1881 —
370, 345°. 5469 ! 1882 -1754, 3449 ;
O O
562
The Gas Engine
CRO
DUN
1884—3537, 15311; 1887—15010;
1888 — 14248, 17413 ; 1891 — 10298 ;
1892 — 2862; 1893—16900, 23075,
24584; 1896-2895
Crossley, F. W., 1874—3205
— and W. J., 1875 — 3221 ; 1877—
2177
Crouan, 1893—8967; 1895—6800;
1896 — 12758; 1897 — 25581, 25582,
27112
Crow, 1896 —4634
Crowden, 1896—2024
Crowe and others, 1883 —2706 ; 1889
—7594
Crozet, 1897 — 15822
Cruikshank (White), 1890—16301
Csonka, 1889—6296
Csonka and another, 1897—7785
Csonka and others, 1894—11119
Culver, 1896—28842
Cumming, 1895—19391
Cundall, J. S. , R. D. , W. D. , & H. C. ,
1896-6974
Cundall, R. D., W. D., & H. C.,
1895—18706
Cunynghame, 1886—10332
Czermac, 1892 — 3292
DAGNALL, 1897-95
Daimler, 1874—414, 605; 1875 — 71;
1879-3245; 1883-5784; 1885-
4315,10786; 1885-13163; 1886-
14034 ; 1889 — 10007
Dale, 1896-8255
Dalton and another, 1879—3467
Daly, 1889—18847
Davey, 1882 -2527, 3787
Davies, 1883—781
Davis, 1894—11108
Davy, 1884—12264 ; 1886—3473 ;
1887 — 7677, 13916, 15658 ; 1892 —
13077; 1893-3401, 4696; 1894—
3485
Dawes, 1891 — 4004 ; 1896 — 24091,
24311
Dawson, 1885—7920 ; 1886—4460 ;
1887—6501; 1890 — 6407; 1891 —
9865; 1892—6952; 1893—1070,
7426; 1894—11802; 1895—12097
Dawson and another, 1897 — 20801
Day, 1891—6410, 9247 ; 1895 —
15514; 1896—11307
Deacon, 1886 — 3010
De Bouilhac, 1897 — 19936
Deboutteville & Malandin, 1884—
3986, 6652, 15248 ; 1885 — 15710 ;
1886—11 ; 1888 — 2805, 8300, 9249 ;
1890 — 14900
De"combe and another, 1894 — 3303
De Coninck, 1896—11573
De Dion and another, 1895 — 19734«
19735, 22402 ; 1896 -9337, 9732
Deed and others, 1896—3503
Deimel and another, 1897—18940
De la Croix, 1897—14649
Delahaye, 1895—19980
Dellatre, 1893-9549
De Palacios and another, 1894 —
13996
De Sales, 1895-23417
De Vesian and another, 1894—12820
De Von, 1897—23361
Dewhurst, 1884—5412
Dheyne and others, 1890—5933,
Dickinson, 1894 — 9305
Dickson, J. F., 1875-744
Diederichs, 1889—14926
Diesel, 1892—7241 ; 1895—4243,
12306
Diligeon & Cie, 1897—23622
Dinsmore, 1885 —13309
Dixon, 1893—2110
Donald, 1879 — 540
Donaldson, 1895 — 6972 ; 1896 — 5277
Doolittle (Still & Bengough), 1897 -
24712
Dorrington, 1890— 6910 ; 1891 — 18276
Dougill, 1881—2122 ; 1883 -3097 ;
1884—12318; 1887 — 10360; 1888 —
9587; 1893—12427; 1897—1400
Dougill and another, 1896 —1327 ;
1897—8529
Douglas, J. C., 1835-6875; 1884-
11750
Dowie, 1892 —20088
Dowsing and another, 1897—6573,
14639
Drake, 1893—16675 (see ante)
Drake, J. A. & W., 1896-12633
Drake and another, 1881 — 4407 ;
1882—1717; 1891—18640, 21015,
21229; 1892—11141,11708,22797
1893-8639
Drysdale, 1893—12600
Ducretet, 1887—9717
Duerr, 1889—20161
Dufrene and others, 1882—1868
Duke, 1894 — 21032
Dulier, 1894—573
Duncan, 1896—10164
Duncan and others, 1895 — 17315
Dunkley, 1896-18520
Dunsmore, 1897-6035
Name Index
563
DUR
GAS
Durand, 1888-6088; 1893—24258:
1895 — 14076
Duric, 1892 —7943, 23800
Diirr, 1892—21952 ; 1893—14572
1895—14385; 1897-20135.
Duryea, 1895—11400; 1896—7036
1897-15233
Dusaulx and others, 1897—29567
Dutton, 1896-28523; 1897 — 21329
Button (Spiel), 1883-4008
Dymond, 1897—22065
Dymond (Meyer), 1897—19642
Dyson, 1882 —5527
EARNSHAW, 1891 — 18715
Eaton, 1894—6647
Economic Motor Co. , 1883 —4260
Edington, J. C., 1854—549
Edison, 1883—1019
Edmonds (Fran9ois), 1879 — 4820
Edmondson and another, 1897 —
20801
Edwards and others, 1896—6933
Edwards, 1880-760; 1881—1765;
1891—17073; 1892—8128, 11962;
1893—14558
Edwards (Petit & Bland), 1892 -260
— (C. J. Ktister), 1896—18988
Electric Motive Power Co., Ld. ,
1896—11058, 18551 ; 1897—5526
Ellerbeck & Syers, 1875 —4326
Ellis, 1892—20660
Ellis and another, 1881 —1409
Embleton, 1887—11717; 1897—4610
Emery, 1867 — 571
Emmet, 1882—397
Emmet and another, 1879 —4101
Enger, 1892—21475
Erben, 1895—20411
Erie, 1897 —9002
Esteve, 1897—11930
Eteve and another, 1881—3113;
1884—2135
Euger, 1895—21484
Evans, 1891—17815; 1893—2788
Evers, 1891—17364
Ewins, 1894 — 12520
Ewins and another, 1881—1388
FABER, 1887-7350
Fachris, 1891—5663
Fairfax, 1884-13573
— (Sohnlein), 1892 — 17391
Fairhurst, 1897—12050
Fairweather (Babcock), 1886—478
Farmer, 1894—7294
Faure, 1894—15152 ; 1896—11342.
21587
Ferranti, 1895—2565
Fessard, 1895 — 21574
Fiddes, 1880 — 5219 ; 1891 — 10333 '•
1893-13518
Fiddes, A. and F. A., 1894 — 4312
Fidler, 1894—2540
Fielding, 1881—532; 1882—994;
1883—3070; 1884-2933; 1886 —
3402, 9563; 1890—6912; 1891 —
19517 ; 1893—108 ; 1894 -11997 ;
1897—11801
Firman and another, 1897 — 20389
Firma Fried. Krupp, 1894—752
Firth, W., 1870 — 2554
Fischinger, 1890-7177
Fistie, 1897 — 22561, 22564
Fogarty, 1873—3848
Forbes, 1892 — 14650
Ford, S., 1874—486; 1881—2280;
1889 — 20115
Forest, 1883-19
Forrest, 1891 — 22559
Foster, 1872 —387 ; 1894 — 2064
Foulis, 1878 — 4630, 4843 ; 1879 —
2073, 4755; 1880—2422, 5090;
1881 — 180; 1883 — 3280
Francois, 1878—2474; 1879 — 4820
Franklin & Dubois, 1869—1375
Fraser, 1895-9188
Frederking~ 1889-20166
Friend, 1888—11614
Fritscher and another, 1897 — 10005
Fryer, 1893 -15405
Furneaux, 1893 —13282
Furneaux and another, 1895 — 4604 ;
1896-24881
GALE and another, 1896—17203
Gallice, 1891-22559; 1897—16074
Gait, 1887—1168, 12749
Gambardella, P., 1859 — 1345
Cans, 1895— 19267 ; 1896—11088
Ganswindt, 1894 — 11804
Gardie, 1883—3383 ; 1886-6161 ;
1888—2649; 1892-16413
Gardner, 1896—8918, 13833
Gardner and others, 1897—24861,
18210
Garner, 1893—18152
Garrett, 1885—4684
Garside, 1892 — 17277
Gas-Motoren-Fabrik Deutz, The, 1885
—11933; 1887—847, 1189, 11503,
002
564
The Gas Engine
GAS
HAN
12187, 17108, 17896; 1888—688,
3020, 3095, 5724, 9602, 14349;
1889—5616, 18746, 20892; 1890 —
1943, 4164 ; 1891—1903, 6717,
8469, 14519, 17724. 22847; 1892-
2728; 1893-735, 9181, 10274;
1894—408, 21829; l895 — 10758 5
1896—795, 3217, 18294
Gascoine and another, 1896—6834
Case, 1888—3964, 6036
Gass, 1895—16556
Gathmann, 1896—24550
Gautier, 1896—313
Gautier and another, 1895—19700;
1896—17221 ; 1897 — 746
Gavillet, 1887—2194
Gedge, W. E., 1865—2600; 1867—
3237
- (Marti & Quaglis), 1882 —
5042
Geisenberger, 1880—533
Geisenhof, 1896-28867
Geisenhof and another, 1894—7542
Genty, 1891—14209; 1892—8678
George, R., 1866-3125
Gessner, 1893—10240
Gibbon, 1892—11962; 1894 — 10623;
1896—22527
Gilbert-Russell, 1892—18118
Gill, J., 1868-2264
Gillespie and another, 1884—3495
- 1886—6612
Gillott, 1885—11558
Gilman & Sowerby, 1825—5150
Girardet, 1889 — 16393
Gladiator, La Soci^te" Franpaise des
Cycles, 1895—20914, 23706
Glaser, 1879-3732; 1882—2008
Glazebrook, J., 1797—2164
— 1801 — 2504
Goddard, 1894 — 25334
Goetjes and another, 1894 — 13996
Golby and another, 1896—18194
Goodrich, 1872—3641
Gottheil, R., 1874—25
Gordon, 1896 — 16348
Gosselin, 1897—22791
Gowlland, 1896—15752
Gowlland, W. & C. S., 1896-14375,
14446
Graddon, 1879—1161, 4483; 1880—
5479; 1881—799
Grant, 1894—2593
Graves and others, 1895 — 22523
Gray, 1885—15194 ; 1891—191, 2053
Green, 1884—8489 ; 1889—16202 ;
1895-11493, 21594
Grelet, 1896—19136
Griffin, 1881—5483; 1883-4080;
1884 — 3758, 11576, 14311 ; 1886 —
15764; 1887—3934, 10460; 1890—
6217, 10952, 19962; 1891—4535;
1892—8733, 16339; 1894—13298
Griffith, 1884—12201
Grist, 1895 — 16096
Grivel, 1897 — 9784, 9963
Grob, 1890-2919, 10718; 1891 —
8821, 9323, 14269
Groth, 1881—1382
— (Daimler), 1883—5784 ; 1884 —
9112; 1885—13163
Grove, 1893 — 12330 ; 1895—19142
Grove and another, 1894—8668,
20192
Guibert and another, 1895 — 13°47
Guillery, 1892—9121
Guthrie. 1882—2337 ; 1884—9001,
10483
Gwynne and another, 1881 — 1409
HADDAN (Schiltz), 1883—4455
- (Gavillet & Martaresche),
1887—2194
(Archat), 1887—9111
(Piquet & Co.), 1894 — 10034
(Pons y Curet), 1894 — 11593
(De Coninck), 1896—11573
(Heinle & Wegelin) 1897—
I9533- .J9534
Haedick, 1889—17008
Hahn, 1887—10176
Haigh and another, 1880 — 1969 ;
1881— 811; 1882-614; 1883 —
25J7
Hale, 1883 — 2192
Haley & Mills, 1875—265; 1877—
3024
Hall, 1890—14382 ; 1896—6590,
11549 ; 1897 — 14826
Hallewell, R., 1875—2826; 1876-
4987, 4988; 1877—819; 1878 —
1798, 5092 ; 1879—1450
Hailing and another, 1895 — 1310
Hamerschlag, 1896—11549
Hamilton, 1888—3546; 1889—16434;
1890 — 6015 ; 1892 — 4189, 10254 ;
1893—21120,24384; 1894—11261;
1897—4963, 25987
Hamilton and another, 1894-18452 ;
1896-731
Handford, 1883 — 1019
Handyside and another, 1881—3536 ;
1892-20088
Hannan, 1886 —2993
Name Index
565
HAN
Hannoversche Maschinenbau Actien
Gesellschaft, The, 1878—1997
Hardaker, 1880—2290
Harding and another, 1895—8197
Hardingham (Cleland). 1891 — 8289
— (Webster), 1896-29718
Hargreaves, 1887—5485 ; 1888 —
10980, 12361, 18761 ; 1889 —
14789; 1897-6651
Harris, 1892—3165; 1894—19894
Hartig, 1885 — 9801
Hartley, 1889—2760; 1890—15309;
1891—21496 ; 1892—17427 ; 1893 —
3332. 397L 10310
Haseltine, G. (Leggo), 1871—2254
— (Goodrich), 1872—3641
— (Brayton), 1874—2209
Haseltine, S., 1852—14086
Hawkins, 1891—9805 ; 1894—24898
— and another, 1897 —21833
Hayot, 1897—19673
Hayward, 1896—11351
Hazard, E. , 1826 — 5402
Hearson, 1886—15955; 1887 — 12592;
1888 — 14401
Heeley and others, 1895—22523
Hees, 1879—3732
Heilman, 1896 —15197
Heinle and another, 1897 — 19533,
X9534
Held, 1891—11628; 1892—17632
Henderson (Eteve & Braam), 1884 —
2135
Henniges, 1880—4159
Henriod-Schweizer, 1894—10788 ;
1897—10097
Henty and another, 1894—20538 ;
1895—18070
Hesketh and another, 1897 — 25856
Hetherington, W. I., 1869—3585
Heurtebise, 1866—3448
Hewitt, 1895 — 11709
Heydemeyer and another, 1897 —
9098
Heys (Langensiepen), 1893—4327
— (Letombe), 1894-24133
— (Heilmann), 1896—15197
Higgins and others, 1896—29747
Higginson, 1890—17371 ; 1891 —
5490 ; 1892-520
Hilderbrand, 1896 — 6915, 12776
Hill, 1884—5007, 12603 1 l8^5 —
7104
Hille, 1890 — 10642
Hilton, 1878—10
Hinchliffe, 1895—15411
Hirsch, 1894—13333, 24089: 1895—
946
HUN
Hitchcock, 1891 -18640, 21015, 21229 •
1892—11141, 117708, 22797
Hock, J., 1874—493
Hockett, 1896—9770
Hoelljes, 1889—12447
Hogg, 1892-14650
— and another, 1894—8668, 20192
Holden, 1896 — 11491, 27602, 27603
Holder, 1883-3336, 5265
Hollingshed & Bower, 1868-2808
Holmes, J. E., 1864—1288
Holroyd and another, 1894—11369 ;
1896-11347
— and others, 1895—24411
Holt, 1884—3893, 8211, 15312 ; 1885
— 3747 ; 1890 — 12314, 20888 ; 1892
—1246, 10437; 1894—4301, 8295,
10113, 14002; 1895—12095; 1896
—4245, 18051 ; 1897-2095
Holt & Crossley, 1879—1912, 4499 ;
1880—3411 ; 1881 — 370, 3450,
5469 ; 1882-3449 ; 1884-3537,
15311; 1888—14248; 1891 — 10298
Hopkins and another, 1879—3561 ;
1883 —2492, 5406 ; 1884 — 11837
Horn (Vandusen), 1891—8032
Home, 1880 — 5024
Hornsby, 1891—17073 ; 1892—8128,
11962; 1893—14558
— and another, 1894—6122 ; 1897—
5147, 17839
— and others, 1896—6933
Hornsby & Sons, Ld. (Burton), 1896
-21877
Horsey and another, 1895—973
Hosack, 1887-888
Houdry and another, 1897 — 10005
Howard and another, 1883 — 388 ;
1895—11282; 1896—2113
— and others, 1894—11101
Howden, 1889—9685
Hoyle, 1895—17560
Huber, 1897 — 29508
Huesler (Grob), 1891—9323
Hughes, E. T., 1872—3481
(Cordenons), 1891 — 2976
Hugon, P., 1860—615, 2902; 1863 —
653, 65986
Hulley, 1893—24584
Humes, 1885-8411 ; 1886—1464,
5597, 11269, 13229 ; 1888—5632
Humphrey, 1895—347
— and another, 1896—28648
Humpidge, 1892 — 3417
Hunt, 1889—9685 ; 1896—16708 ;
1897—13988
Hunter, J. M., 1868—2680
Hunter, J. W., 1897 — 1402, 18202
566
The Gas Engine
HUN
KOS
Huntington, 1889—14592 ; 1891 —
9268
Hurcourt, 1868—354
Hurd, 1879 — 2193
Huskisson, 1896 - 18202
Hutchinson, 1880—5471 ; 1882 —
2329 ; 1886—4785, 12086, 14269
Hutter, 1892 — 3292
Hydes & Bennett, 1869—3087
IBBETT, 1896-6740
Ide, 1896-24804
Iden, 1897 — 26898
Imray, J., 1873— 1946 ; 1888 — 1336
— (Glaser), 1889 — 8778
— (Schweiser), 1883-836
— (Weilbach), 1889-3887
Instone, 1892 — 3047
Ireland, 1885—1478
Irgens, 1891 — 11138
— and others, 1897—28821
Ironmonger, 1897—20880
JAHN, 1896—17448
Jakeman and another, 1894—7485
J ames , 1 895 — 2638 ; 1 896 - 27408
Janiot, 1889 —17295
Jastram, 1892 — 21857, 21858
Jenkin, F. , 1874 - 2441
Jenner, 1880—3607
Jensen, P., 1872 — 1423
— (Weilbach), 1888—15858
— (C. & A. White), 1897—20455
Johns, 1884—5302, 5303
Johnson, J., 1841—8841
— (Tower), 1895—5373
Johnson J. H., 1860-335; 1861—
107 ; 1874—2795
— (Bisschop), 1882—579
(Franpois), 1878—2474
— (La Soci^te" des Moteurs
Labrigot), 1877—3159
— (Wertheim), 1876—3444
Johnson, 1879—2732 ; 1880 — 1131
— (Deboutteville & Malandin), 1884
— 3986, 6652, 15248 ; 1885—15710;
1886—11 ; 1888—2805
— (Genty), 1891—14209; 1892—8678
— (Hille), 1892—13088
— (La Socie'te' des Tissages et Ateliers
de Construction Diederichs), 1887
— (La Socie'te" Salomon), 1888—2804
— (Lenoir), 1883— 5315; 1885—610
— (Pieper), 1891—19772, 19773
Johnson & Cropper, 1878 — 3444
Johnson, C. M., 1896-21675, 27568
1897 — 2666, 10519, 12199, I2942A,
30266
- W., and another, 1896—23110
Johnston, 1888—8252 ; 1895 — 18379,
20189 ; 1896—18585
— and another, 1896 — 23350
ones, 1896—29610 ; 1897 — 16977
ulien, 1897 — 18005
unkers, 1892 — 14317
ustice (Hale), 1887—11255
Backeljau), 1884—11361
Baldwin), 1890-12678
Osam), 1881—3415
Hale), 1883—2192, 5265 ; 1885 -
10401
— (Taylor), 1886—4881
KABATH, 1883—999
Kane, 1895—20305
Karavodin, 1895 — 749
Karger, 1895 — 1071
Kaselowsky, 1890—4574 ; 1891 —
11680
Katz, 1897—15908
Keating and another, 1896—6573
Kelly, 1892 — 11598
Kempoter, 1885—1581
Kenworthy and another, 1879 — 3467
Kerr, 1891—21496 ; 1892—17427 ;
I893-3332. 3971, 10310
Kerridge, 1897 — 29361
Kesseler, 1880 — 4159
Key, 1891—6949
Kidd, 1876 — 1034
Kierzkowski, De, 1876 — 3191
Kinder & Kinsey, 1867—499
King, 1879-4337; 1881—4223; 1883
—638 ; 1884—7284-7288 ; 1885—
1478, 1700
King (Connelly), 1890—5621; 1891 —
14002
Kirchenpauer, 1883 — 3272, 5042
Kirkhove and another, 1881 — 3561
Kirkwood, Lascelles & Hall, 1874-
4410
Klaus, 1897—9463
Klunzinger, 1895—8355
Knight, 1887—2783,13555; 1888 —
9691; 1889—6831 ; 1891 — 20926;
1892-23323; 1894—17233
Kolbe, 1895—4972, 8815, 8817
Korting, 1883—2702; 1887 — 12863;
1888—17167
Kortung, 1881—2931
Kortynski, 1888—6468
Kosakoff, 1887—12696
Name Index
567
KOS
Kostovitz, 1888—8273
Krauss, 1879—309
— and another, 1895 — 9922
Kummer & Co., 1890 — 7177
Kiister, C. & J., 1896—18988
LACASSE, 1896—16997
Lacld, 1883-4242; 1895—14242
Lake (Backeljau), 1893 — 5256
— (Beckfield & Schmid), 1890—2647
Beuger), 1888—5204
Brayton), 1890—11062
Breittmayer), 1880—3140
— (Fogarty), 1873-3848
— (Foster), 1872—387
— (Gardie), 1883—3383
— (Lay), 1878—4782, 4987 ; 1880—
2182'; 1881 — 4830
— Maxim), 1883—132
— Schmidt), 1872—3228
— Secor Marine Propeller Co.),
1889-5165
— (Spiel), 1888—5914
— (Wertheim), 1877 — 1063
— W. R., 1872—387, 3228; 1873—
3848
— (LaSoci£te Fritscher et Houdry),
1897—1160
— (Die Firma Fried. Krupp), 1894 —
— (La Socie"te Main Guiste & Co.),
1897—13734
Lalbin, 1888—16268
Lallement and another, 1881—3113
Lamena, 1894 — 11726
— and another, 1894—3303
Lamy and another, 1897—11951
Lanchester, 1889—12502, 19868;
1890-5479, 19513, 19775, 19846;
1891 — 4222, 11861, 14945, 21406;
1892—4210, 4374; 1894—22946;
1895—15045, 18908; 1896—5814,
7603, 18829, 22935, 24805
Landry and another, 1896—9259
Lane, 1887 — 12591 ; 1896—2290,
10018
Langen & Otto, 1866—434; 1867—
2245
Langensiepen, 1893—4327
Langou(Marlin), 1893—2596
Larrivel, 1888 — 13414
Lascelles, C. F. E., 1874—3257 ; 1876
— 1961
La Soci£t£ Anonyme d'Automobil-
isme et de Cyclisme, 1897-11710
— des Precedes Desgoffe et de
Georges, 1896—7250
LON
La Soci^te" Main Guisti & Co. , 1897—
13734
— Fritscher & Houdry, 1897 —
1160
Laurent, 1882—6130
Lausmann, 1894 — 12917
Lawart and another, 1881 — 1074,
4589 ; 1882—1868
Lawson, 1880—3913 ; 1884—13935 ;
1889—7640; 1897 — 18531
Lazar and others, 1894 — 11119
Lea, 1887 — 13436
Le Brun, 1897—7333
Ledin, 1896—5860
Lee, 1891—18424
Lees, 1897—5736
Lefebvre, 1897—10261
Leggo, 1871-2254
Lehmbeck and others, 1897 — 15980
Leichsenring, 1878—3050
Leigh (Spiel), 1886—2272, 6165 ;
1892—2854
— (Forrest & Gallice), 1891 — 22559
— (Gosselin), 1897 — 22971
Leipziger Dampfmaschinen und
Motoren Fabrik, 1894—20123
Le Melle and others, 1896—24144
Lenoir, 1883—5315; 1885—610
Lentz and others, 1890—21165
Lepape, 1896—28583
Lesnard, 1869—1748
Letombe, 1894—24133; 1897—13325
Levasseur, 1891—9006
Levassor, 1881 — 2765
Lewis, 1896—2171
L'Homme, 1896—29854
Lieckfeld, 1883—2702
Lindahl, 1893—8158
— and another, 1895 — 1310
Lindemann, 1889—16391 ; 1891 —
4862 ; 1894—263
Lindley, 1882—703; 1883—3568;
1887—2520, 11345 ; 1888—7547,
16057 ; 1889—20033 ; 1894—24949
Lindner, 1890—1150
List, 1887—12696
— and others, 1893—7433, 12388
Lister, 1895—20703; 1896 — 21136;
1897—679
Livesey, 1880—2299, 5130
Livingstone, 1895 —25024
Lloyd, 1897-29593
Lobet, 1890 — 1979
London Economic Motor and Gas
Engine Co., 1886—12068
Lones, 1895 — 1046 ; 1896—23138
Longuemare, 1896—11475; 1897—
7969
568
The Gas Engine
LOR
MON
Lorenz, 1895—13675, 14361
Loutzky, 1897—12924
Love, 1891 — 5250
Low, 1894—6755
Lowne, 1889 — 17344
Loyal, 1896—9052
Lucas, 1881 — 3527
Luedeke, J. E. F., 1857-2408
Luiford, 1876—2824 ; 1877—1470 ;
1878—942; 1879—1500; 1880 —
330 ; 1881 — 2990 ; 1883 — 326 ; 1884
—5797
Lutzmann, 1896—11914
Lyon, 1896—28117
MACALLUM, 1886—13517 ; 1891—
816; 1894—17549
Macdonald, 1895—12409; 1896 —
MacFarlane, 1880—4547
Macgeorge, 1885 — 6880
MacGillivray, 1882—3819 ; 1884—
14765
Mackenzie, 1885—3917
— (Crouan), 1895—6800
— and another, 1896 — 28527
Macneil, T. T., 1866—27
Magee, 1884-9544; 1885-6763,
11422; 1886 — 665; 1892 — 9674;
1895—21774; 1896—11506
Malam and another, 1880 — 1692, 3685
Malandin and another, 1884 —3986,
6652, 15248; 1885-15710; 1886 —
ii ; 1888—2805; 1890 — 14900
Mallet, 1896—4618
Marcet and another, 1897 — 25856
Marchant, R. M., 1874—509, 3189,
3190 ; 1883—1501
Marconnet, 1897 — 17842
Marcus, 1882 — 2423 ; 1896—2874
Marengo and another, 1896— 16277 A
Marks, J., and another, 1896—1327 ;
1897-8529
Marks, G. C., 1895—22690
— (Hirsch), 1894—13333, 24089 ;
1895-946
(Chaudun), 1897—11015
— (Bouvier), 1897—8064
Marsden, 1896—30075
Marshall, 1860-2743
Martaresche, 1887 — 2194
Martel, 1896—21743
Martha, 1897—20617
Marti and another, 1882 — 5042
Martin, 1893 — 2596
Martindale, 1897 — 2123, 7979
Martineau, 1896 — 4492
Martini, 1883—1060
— and another, 1897 — 18940
Mason and another, 1897 — 24432
Matteucci & Barsauti, 1854 — 1072 ;
1857 — 1655; 1861—3270
Maxim, 1883 —132
Maxim, H. S., 1896—1404, 2436;
1897—10620
Maxim, H., 1896—9526; 1897 — 3025
May bach, 1892—16308 ; 1893 — 16072,
16985; 1896-7940, 12337
Maynes, 1882—5510
Mazurier and another, 1896—28979
McAllen, 1889—13572
McDowall, 1887 — 4403
McGhee, 1885-6763; 1886—1433,
14578 ; 1887—11678 ; 1888 — 3427 ;
1890 — 12690 ; 1891—19086 ; 1893—
1277; 1896-9199
McMillan, 1889—5397
McNeill, 1884—6784
McNett, 1889—12045
Meacock, 1894 — 1121
Meekins, F. M., 1859—784
Melhuish, 1890—5192 ; 1895 — 9038 ;
1896 — 15127
— and another, 1895—11925
Mellin, 1893—2523
Menard, 1891—12981
Menzies, 1888-16605
Merichenski and another, 1895—8120
Merlanchon, 1863-1449
Merril and another, 1896—14959
Merry weather and another, 1894—
7485
Mewburn (Goubet), 1882—5506
— (Pro well and others), 1890 — 7177
— (Bates), 1896—26261
Mex, 1895—9964
Michael, H., 1860-878
Michaux and others, 1895 — 17315
Michels (Grob), 1692— 5819
Middleton, 1887 — 14269 ; 1888—9725 r
1890 — 16301 ; 1896 — 27276
— and another, 1895—16891
Mietz and another, 1897—24096
Milburn, 1886 — 2993
Miller, 1889—2637 ; 1891—834, 21529
Millet, 1889—5199; 1895—1580
Mills, 1883—5721 ; 1885—5971
Mills & Haley, 1875-265; 1877—
3024; 1879—5052
Mitchell, 1897 — 11520
Mitchelmore, 1894—5681
MofFat and another, 1895 —8120
Molyneux and another, 1897 — 16943
Mondey and another, 1896—9092
Monin and another, 1896—23492
Name Index
569
MON
PET
Monkhouse and others, 1896—19211
Montelar, 1881 — 5534
Moram, 1892—6655
Morcom, 1893 — 8095
Morgan, 1893—12732
Morris, 1888—11161
Mors, 1896—10141
Motive Power and Light Co. Ld.
and another, 1896 — 23296
Mottershead, 1890—17299
Muirhead and another, 1881—4407;
1882—1717
Muller, 1880—4819
— and others, 1884 — 16634
Munden, 1884 — 4591; 1896—21274
Myers, 1884-848 ; 1897—6688
NAISMITH, H. A., and another, 1896
—14959
Nash, 1883—2561, 5543, 5632, 5633;
1885 — 14394 ; 1886—493, 667° 1
1888 — 10350
Nasmyth, J., 1859—1227
Nayler, 1896 — 24905
— and another, 1895—24235
Neil, 1896 — 4153, 18304
Nelson, 1888—8009; 1889—5397
New, 1897 — 16729, 29467, 29468
Newhall, 1887—516
Newman and another, 1881 — 1388
Newton, A. V., 1852 — 14150 ; 1855 —
562
— (Munay), 1886—13727
Newton, 1884 — 15633 ; 1 88^—7929,
Newton, A. V. (Emery), 1867—571
Newton, W. E. (Marshall), 1860—
2743
- — (Barsauti & Matteucci), 1861 —
3270
— (Babbitt), 1867—3690
— (Bisschop), 1872—1594
Newton & Cowper, 1879 — 1947
Nicholson and others, 1896 — 29747
Nicolas, 1897 — 5522
Niel, 1882—1026 ; 1883—3135 ; 1886—
4234; 1887—11567; 1889—875,
17295; 1893—14546
Niemczik, 1891 — 8821 ; 1895 — 546,
1922
Niepce, J. C., 1817 — 4179
Nixon, 1886—7658
Nobbs, 1882—2257
Noble, 1892 — 919
Nordenfelt and another, 1894 — 11526
Norgrove and others, 1897 — 913
Normandy, A. L., 1867—633
Norrington, 1884 — 10062
Norris, 1890—11755 ; 1892 — 1768,
4352, 4375
Norris and another, 1894 — 20538 ;
1895 — 18070 ; 1896—26292 ; 1897 —
7770
Northcott, 1880—3176
Nunn, 1895 — 20666
Nuttall and another, 1880—1969 ;
1881— 811 ; 1882—614 I 1883—2517
O'BRIEN (Triouleyre), 1896—23802
Odling, 1882—5825 ; 1883—130
O'Donnel (De Bouilhac), 1897—
19936
Oechelhaeuser, 1888 — 2913; 1889 —
4710; 1892—14317; 1894—24994
Often, 1890—13594
— and another, 1897 — 11414
Ogle, 1892—9448
Okes, 1893—6453, 9216
Oldfield, 1891—18715
Ollivier, 1897—4580, 4888
Ord, 1881—798, 3275
Osan, 1881—3415
Otto, 1876—2081 ; 1878—1770 ; 1881
—60 ; 1883—1677 ; 1890—4823,
5273, 5275, 5972, 6113
Otto & Crossley, 1877—491
Ovars, 1890—13352
Owen, 1892—6240 ; 1893 — 7023
PAGET, 1896—12539
Palmer, T. N., 1872—1126
Park, 1884—5435
Parker, 1884 — 13776
Partridge, 1889—6161
Pascal, J. B., 1861—166
Pass, De, 1881—2931
Paterson, 1897 — 4299
Paton, 1889—441 ; 1892—17732
Payne, 1896—27535
Peebles, 1893 — 10801
Pennington, 1895—23771, 25050 ;
1896—996, 7549, 17573, 27207,
27208:;. 1897— 4556
Pennink, 1895 — 2594, 12131
Perkes and another, 1896—30162
Perot and another, 1896—23492
Perrett, 1886—2653
Perrollaz, 1891—20845
Petavel, 1896—23142
Fetter, 1896—9256'
Pettit, 1892—260
Petre"ano, 1896 — 23270 ; 1897 — 17127,
18804
570
The Gas Engine
PET
RID
Petre"ano and another, 1897 — 17317
Peugeot, 1896—11078 ; 1897 — 9907
Philipot, 1897—878
Philippi, 1883 — 3272
Pickering, 1883—3708
— and others, 1894—15061
Picking and another, 1879—3561 ;
1883 —2492, 5406
Pieper, 1891—19772, 19773
— (Krauss), 1879—309
— (Kortingand another), 1883—2702
— (Schaeffer), 1878—290
Piercy, 1884—5797
Piers, 1888—10983, 10984; 1889—
2144; 1892—15247; 1894—10451,
10452 ; 1895 — 1623
Pilcher, 1897 — 11619 '
Pillon and others, 1896—24144
Pinchbeck, J., 1865 — 905
Pinkert, 1896—6872
Pinkney, 1881—2645; 1885 — 1218;
1887—1986; 1888—19013; 1889 —
3525; 1890 — 17167; 1891—103,
7313, 11138, 17955; 1892—3203,
20683; 1893—22753; 1895—644,
21521 ; 1897 — 8318, 22310
Pinkus, H., 1839—8207; 1840—
8644
Piquet and Co., 1894 — 10034
Platts and others, 1894—15061
Plessner, J. M., 1870—194; 1871 —
2587
Polke, 1896—11992
Pollard and another, 1897 — 8547
Pollock, 1884 — 4639 ; 1892—8401
Pollok and another, 1894—23802
Pons y Curet, 1894 — 11593
Pool, 1895—10621 ; 1897 — 12117
Pope, 1885—3471
Poron, 1897 — 1475
Porteous, 1882—2058
Potter, 1896 — 30010
Pottle, 1880—9
Poultney and others, 1897—913
Power, 1896—26879
Pratis and another, 1896— 16277 A
Prentice, 1884—14512 ; 1897—4879
Prestwick and another, 1895—22161
Priestman, 1885 — 10227 ; 1886 — 1304
16779; 1887—1454, 5951, 12432;
1888 — 270 ; 1889—6682 ; 1891 —
3830, 4142, 5250 ; 1892—21342 ;
1893—12843, 20808 ; 1894—15721 ;
1896—6738, 24457
— and others, 1897 — 23582
Prince, 1895—17282 ; 1896—6718
— and others, 1896—19211
Proell and others, 1890 — 7177
Protector Lamp and Lighting Co.,
Ld., 1895 — 22161
Publis, 1889—1957
Pullen, 1893—12917
Purchas, 1888—11614
Purnell, 1884 — 12431 ; 1888—10165 r
1891—7047
Pursell, 1879—1727, 4396 ; 1880—
3869
Putsch, 1897—8056
QUACK, 1883—4023 ; 1888—2466
Quaglio and another, 1882—5042
Quentin, 1896—23005
Quick and another, 1881 — 5575
Qurin, 1893—16290
RACHOLZ, 1883—4193
Rackham and another, 1895 — 3783
Rademacher, 1892—21917
Ramsbottom, 1878—228
Rankin, 1892 — 826
Rapier, 1883—5928
Ravel, 1887—16257 ; 1897—27301
Rayner and others, 1897 — 13721
Read and another, 1896 — 26399
Reddie (Murray), 1884—12714
Redfern (Gardie), 1886—6161
- (La Socie"t£ Anonyme des Mo-
teurs Thermiques Gardie), 1892 —
16413
— (McDonough), 1884—13283
— (Nordenfelt & Christophe), 1894 —
11526
— (Sack & Reunert), 1876—3370
— (Smyers), 1885 — 11290
Reeve, 1897 — 7098
Regan, 1884—16890; 1888—15448
Reid, 1893 — 2523
— (Bray ton), 1894—6138
Rennes, 1891—6727
Repland (Niel), 1889—875
Reynolds, J. W. B., 1844—10404;
1896—3331, 17926
Rhodes, 1881 — 5259
— and others, 1880—4398
Ricci, 1897—16380
Richard and another, 1897 — 11951
Richards, 1888—15158
Richardson, 1890—11755; 1892—112
1768, 4347, 4352, 4375, 5972
— and others, 1896—6738 ; 1897 —
23582
Ridealgh, 1887—4511 ; 189!— 6598,,
19811
Rider, 1879—2191
Name Index
571
RID
SHE
Ridley, J. D., 1874—777
Rigg, 1885-6047
Ringelmann, 1897—2595
Rippingille, E. A., 1868—3264
Rixson and another, 1897 — 24432
Robert, R., 1853—362; 1892—3574
Roberts, 1877 — 711
— and others, 1896—6933
Robertson, J., 1868—3146
Robinson, J., 1843—9972 ; 1880—117,
2344, 4260, 5347 ; 1890—14787 ;
1891—1083, 20262, 20745 I 1892 —
9161 ; 1893—8864 ; 1894—23028
— and another, 1897 — 16943
Robson, 1877—2334 ; 1879—4501 ;
1880—4050; 1881—2083; 1883—
5331 ; 1886—15307 ; 1890—9496
— and others, 1896 — 10690
— and another, 1895 — 4786
Rockhill, 1884—2289 ; 1886—13655 ;
1891—3669
Roger, 1895—16362 ; 1896—20428
Rogers, 1885—15737; 1889—10286;
1895—24792
Rogerson, 1884—2088
Rolfe and another, 1897 — 5147
Rollason, 1886—7427, 12368 ; 1888--
3546 ; 1889—16434 ; 1892—1879 ;
1893 — 5005 ; 1894—5218
— and another, 1896—731
Romer and another, 1896 — 30162
Rook, 1886—1696
Roots, 1886—8210 ; 1888—9310, 9311,
11067, 15882, 16220; 1880—3972,
9834; 1890—14549, 19559; 1891—
18621, 19275 ; 1892—23786, 24065 ;
1893—9618, 22181, 23571 ; 1894—
7538, 17308 ; 1896 — 2138, 14756,
23604 ; 1897—5882, 9722, 20761
Roser and another, 1896 — .28979
Ross, 1887—4403
— and another, 1897 — 23541
Rossel, 1897—12553
Rotten, 1889—17024
Rousselot, J. S., 1857 — 1754
Rouzay, 1891 — 2815
Rowden, 1888—5774, 9705; 1889—
10669 ; 1897—7074, 19910
Rowbotham, 1896—4184, 12943,
14829, 15279, 27315
Rowlingson (La Socie'te' Diligeon et
Cie), 1897—23622
Royer, 1897—8471
Royston, 1885—13623 ; 1888—14614
Rub, 1896—7566; 1897-659
Ruckteschell, 1885—15475
Rumpf and another, 1896—18194
Russ, 1882—2231, 5371 ; 1897 — 16631
Russell, 1892—18118
Russom, 1883—3041
Ruud and another, 1897 — 13517
Rydill, G., 1873—329
Ryland, 1893—20007
SABATIER and others, 1893—608
Sack & Reunert, 1876 — 3370
Sanborn, 1892 — 16365
Saurer-Hauser, 1894 — 16230
Sayer, 1890—18161 ; 1892—13939
1893 — 6204
Schaefer and others, 1897 — 15980
Schaeffer, 1878—290
Schiersand, 1890—11834
Schiltz, 1881—3330 ; 1883—4455 ;
1885—12896 ; 1886—10480
Schimming, 1889—4796 ; 1894 —
Schmid, 1887 — 14952
Schmidt, 1872 — -3228
Schmitz, E. N., 1871 — 1724
Schnell, 1888—7893
Schoenner, 1894 — 10511
Schollick, E. J., 1853—1248
Schoufeldt and another, 1881—1382
Schultze, 1891—8821
Schumacher and others, 1894 — 15061
Schwarz, 1892 — 1814; 1894 — 7357
Schweizer, 1883—836
Schwicker and another, 1896 — 23860
Scollay, 1890—2207
Scott, 1894—9403
— and another, 1897 — 21833
Scutz and another, 1897—9098
Seage, 1890-8431
Seal, 1891—18621
Seaton, 1882 — 2751
Seek, 1891 — 22834 ; 1892 — 10091 ;
1896—8089
Secor Marine Propeller Co., 1889 —
5l6S
Sello and others, 1897—15980
Sennett, 1892 — 7943, 23800
Serrell, 1883—4242
Serret, 1895—1884
Settle, 1891—12330
Seunier, 1897 — 16411
Shann, 1884 — 6597; 1897 — 8100
Shann, M. H. C. & R. E. C., 1897—
736
Sharpneck, 1890—18645
Shaw, R., 1867—422; 1879—392;
1881—5178 ; 1886—2447 ; 1888—
18377 ; 1891 — 18020 ; 1897—20236
Shepard, E. C., 1850—13302
572
The Gas Engine
SHE
TEI
Sherrin, 1893 — 18152
Shiels, 1891—17033 ; 1893—779
Shillito (Capitaine), 1886—1797
— (Grob and others), 1891—8821
— (Swiderski & Capitaine), 1892—
6872
— (The Leipziger Dampfma-
schinen und Motoren Fabrik), 1894
— 20123
Shuttleworth, A. & F., 1895—15310
- and others, 1893—531, 17784 ;
1896-3503
Siemens, C. W., 1862—2143; 1881 —
2504. 5350
Simms, 1893—15947; 1896—10424;
1897—12954, 15348
— (Maybach), 1896—7940
Simon, 1876—3435 ; 1877—2749 ;
1879—3233 ; 1885—1363 ; 1888-
16183 ; 1892—926
— & Miiller, 1877—2621
— (Kindermann), 1877 — 4937
-JL. &R.), 1878-433
— and another, 1878 — 4979
— (Todt), 1879—750
— & Wertenbruck, 1880—4881 ; 1881
— 4288
Simpson, 1896—4924, 27184 ; 1897
—23357
Singer, 1894—4959, 4960 ; 1896—
16512
Sington, 1887—4564 ; 1888—512
Sittori, 1893—24612
Skene, 1882 — 1590 ; 1884 — 454 ;
1886—2174 ; 1891—5747 ; 1894—
7023
Skinner, 1882—1910
Smith, 1882—4418 ; 1889-2772 ;
1895—16068 ; 1896—786, 12041,
19232, 20449, 25642 ; 1897 — 14298
— and others, 1896—19211, 30026
Smithurst and others, 1893 — 14212
Smyth, W., 1867 — 1392
Smyth & Hunt, 1875—2334
Snelling, 1889 — 20703
Snoxell, 1892 — 3417
Snyers and another, 1881 — 3561
Sbhnlein, 1892—17391 ; 1896—1789
Sombart (Buss), 1879—1933 ; 1880
— 1736; 1881 — 320; 1882—2057;
1883 — 5923 ; 1884—8232
Sondermann, 1894 — 9723
Soul, M. A., 1872—821
Southall, 1885—12424; 1886—15472;
1888—7934 ; 1889—5072 ; 1891—
9038 ; 1892 — 1203, 18020, 18109 :
1894—5493 ; 1895-6383, 18995 ;
1896—22375; 1897—17204
Southey and another, 1895— 15694^
16157, 22347
— and others, 1896 — 11058, 18551 ;
1897—5526
Southwell, 1895—6974
Sowerby & Oilman, 1825—5150
Spiel, 1881—4244; 1883—4008; 1885
— 3414 ; 1886 — 2272, 6165 ; 1887
—3109 ; 1888—5914 ; 1892—
2854; 1893—16410; 1895—13975,
14009
Stallaert, 1890—12760
Stanley, 1895—3357
Steel, 1883—1116
Stephens, 1896—18831
Stephenson and another, 1897 — -4528
Stern and others, 1881 — 3536 ; 1884
— J373
Sterry, 1887 — 125
Stevens, B. F., 1864—1599 ; 1887—
4843
Still and another, 1897 — 24712
Stillwell, 1896—15267
Stitt, 1888—6794
Stoke, 1893 — 23175
Stout and another, 1885 — 11555
Straker and others, 1897 — 13721
Street, R., 1794 — 1983
Stroh, 1892—18808 ; 1897—2849
Stuart, 1886—9866, 15319 ; 1888 —
10667, 14076 ; 1889—14868 ; 1890—
7146, 12472, 13051, 15994 I 1892 —
3909, 22664
Stubbs, 1888-7927
Sturgeon, 1885—8897 ; 1887—4923
7925, 16309, 17353
Sturmey, 1896—2394
Suberbie and others, 1895 — 17315
Sudlow, W. E., 1873 — 272
Sumner, 1882—1360 ; 1889—7522,
7533
Sundberg, 1897—7526
Susini, De, 1892—14713
Swiderski, 1892—2495, 6872
— and another, 1896 — 23860
Switz and others, 1893—23735
Syers & Ellerback, 1875—4326
TANGYE and another, 1896—23110
Tangyes, Ld., and another, 1895—
4786 ; 1896—10690
Tavernier, 1887—4757; 1888—5628;
1889—1603, 7069 ; 1896—7609
Taylor, 1886 — 15327; 1889—708
1896—3062
Teichmann, 1882 — ^008
Name Index
573
TEL
Tellier, 1887—2631 ; 1889—7140
Tenting, 1895 — 23412
Terry, 1894—12840, 18443
Thacker, 1876—88
Theerman, 1889—5301 ; 1890—1586
Thomas, 1887-2368
— and another, 1896 — 10399, 16660
Thompson, 1896—5598
— (Covert), 1889—12472
— (Durand), 1888-6088
- (Diirr), 1893-14572
— (Geisenberger), 1880—533
— (Marcus), 1882—2423; 1883 — 2790
— JO' Kelly), 1882-11598
— (Regan), 1888—15448
— (De Palacios and Goetjes), 1894 —
— (De Von), 1897—23361
— (Irgens & Brunn), 1897—28821
— (Julien), 1897—18005
— (Loutzky), 1897 — 12924
— (Schoenner), 1894—10511
— and another, 1895—23740 ; 1896—
17203
— - and others, 1896 — 24144
Thomson, 1896—27979
— and others, 1894—5843
Thornton and another, 1897 — 8547
Ticehurst, 1891 — 8251
Tipping, 1893—16079
Toll, 1896—30045
Tomkin, 1881—5201 ; 1883 -5976
Tomlinson, 1896—11481, 28514 ;
1897-18546
Torat>sa, C. j. B., 1856—1807
Torrey and another, 1897—9929
Touche, La, 1890—2384
Tourney, 1897—6645
Tower, 1895—5373
Townsend, 1883—781
— and another, 1895 — 6523
Tracy, 1887—1168, 12749
Treeton, 1885—8584
Trewhella, 1891—3948 ; 1893—5456
Triouleyre, 1896—23802
Tubb and another, 1896 — 9092
Turner, F. W., 1873—4088; 1879 —
1270; 1880—3182; 1882—362;
1884—16698; 1888-4057; 1894 —
22891 ; 1896—29067
— and another, 1895—8197 ; 1896—
26399
Turnock, 1887—8 ; 1895—18794
Tyler and another, 1894—12820
ULENHUTH, 1897—15983
Urquart and another, 1897 —5618
WEL
VALLEE, 1897 — 4640
Vanduzen, 1891 — 5158, 8032
Vaughan-Sherrin, 1897 — 11334
Vaughan, E. P. H.( 1870—1352,
2959
Venables and another, 1896—23604 ;
1897 — 5882, 9722
Vera, P., 1875 — 175
Vermand, 1890 — 13019
Vermersch, 1894—13524
Villeneuve, A. H., 1870 — 440
Vogelsang, 1890—10642
Vollmer and another, 1896 — 19061
WADSWORTH and another, 1896—
2753
Walch (Dorrington & Coates), 1891
—18276
Walker and another, 1882—6136;
1893—7292
Wallace, 1884—10364
Waller, 1878 — 2901 ; 1891 — 14457
Wallman, 1895—3923
Wallwork, 1887 — 4940, 7925, 17353
Wane and another, 1895 — 973
Warner and another, 1895 — 3783
Warsop, 1885—7104 ; 1895—23879
Washburn, 1895 — 21993
Wastfield, 1881—2967 ; 1882—659,
4755- 47731 1883-1098, 5956;
1887-7771
Watkinson, 1891 — 14134
Watson, 1881—1723, 1763, 2919, 4137,
4608 ; 1882 — 678, 2342, 5782, 6214
Wattles, 1893-23379; 1897—14397
Watts, 1882—4418
Weatherhogg, 1878—3972 ; 1881—
4402 ; 1883—499 ; 1884—4880 ; 1885
— 6565; 1886—8436; 1889 — 8013;
1891—1447 ; 1895—16703
Weatherley, 1895 — 7197, 7747
Webb and another, 1895 — 23740
-J-. 1853—1577; 1892—11928
Webster, 1896—29718
Wegelin and another, 1897—19533,
X9534
Wehrte and another, 1895—19700 ;
1896 — 17221; 1897 — 746
Weigand, 1884—6662
Weilbach, 1888—15858 ; 1889—3887
Weisman and another, 1894 — 11369
Weiss, 1891—3261
— and another, 1897 — 24096
Welch and another, 1883—5928 ; 1886
—1696
Welford, 1891—6598
Wellington, 1891—11851
574
The Gas Engine
WEN
YOU
Wenham, F. H., 1864—1173 ; 1881 —
867; 1896-4938
Wertenbruch, 1880—4881 ; 1881 —
4288 ; 1891—3682
Wertheim, 1877 — 1063
Westinghouse and another, 1897 —
Westwood and others, 1897—913
Wettor ( Rademacher), 1892 — 21917
— (Gerson & Sachse), 1893—153
Weyhe, 1877—4052
Weyland, 1894 — 3122
Weyman, 1891—18640, 21015,
21229; J892 — 11141, 15417,20660,
22797; 1893—2912; 1894—15272
Wharry, 1889—10286
White, 1890—16301; 1895 — 21912;
1897—20455
— (Brown), 1897—14814
— and another, 1895 — 16891
Whitehead, 1883—1116, 2927
Whittaker, 1882— 5819; 1892—16986
Whittam and others, 1894 — 15061
Whyte and another, 1894—23802
Wigham, 1879 — 4485; 1880—5269;
1881—2564
Wilcox, 1885—15874, 15875, 15876
Wildt, 1895—6151
Wilkinson, 1890 —10051 ; 1892 —524 ;
1893-8409; 1896-20655
Williams, 1879—4340; 1881—3715,
5456; 1883—300, 3069; 1887 —
16029, 16144; 1888—10469, 14831 ;
1889—3820; 1891—970, 1299, 15078
— and another, 1880—1692, 3685 ;
1883—4816
— and Baron, 1879 — 2; 1895—10245
Williamson and others, 1883—4816,
5570; 1884—9167; 1885—1478
Wilson , 1 880 —3652 ; 1 884 — 1 2776 ;
1888—4944 11896— 14731
— and others, 1871 — 3121, 3122 ; 1878
—4760
— and another, 1895 --24235
Wimshurst, 1885—15936; 1897 —
ion, 8822
Winckler (Jastram), 1892—21857,
21858
Windisch, 1893—15900
Winton, 1897-900, 1598, 1694, 1695
Wirth (Humboldt Manufacturing
Co.), 1876—1520
— (Bernstein), 1884—1457
— (Sohnlein), 1883—5297; 1884 —
4736
Wisch, 1896—23462
Wise (Buckeye Manufacturing Co.),
1895-23113
Wiseman and others, 1895—24411
— and another, 1896 — 11347
Withers, 1882—417 ; 1891—9931 ;
1894—24239
— and another, 1895—12287
Witlig & Hees, 1879 — 3732
Wolfmiiller and another, 1894 —7542
Wolstenholme and another, 1882—
2753; 1885—8160; 1886—15507,
Wood, 1896—14212, 28892
Woodhead, 1883 — 21 ; 1884—2715
Woodman and another, 1897—11547
Woolfe, 1879—2152
Wordsworth, 1880—2181 ; 1882 —
703; 1887—11466; 1888—7521
— and others, 1881—4340; 1882 —
2753; 1883—3568; 1885—8160;
1886—15507, 15507A; 1888—11161 ;
1895—24411
Worssani, 1882 — 2126
Wrede, F., 1853-1648
Wright, L. W., 1833-6525
— and another, 1885 — 1703 ; 1886 —
YATES and others, 1894—5843
Young, J., 1872—2293
— (Gardner), 1896—8918,13833
— and others, 1896—6933
575
GENERAL INDEX
ABE
ABEL, SIR FREDERIC, on gun-cotton
explosions, 88
— flash test apparatus, 395
Absolute indicated efficiency of
Crossley Otto engines, 376
Absolute efficiency, increase of, 384
Acme compound engine, 332-339
Actual indicated efficiency, 117
Adiabatic line, 40
on Atkinson diagram, 281
and isothermal expansion dia-
gram, 384
Admission velocity of gases in old
type Otto, 305
— velocity of gases in modern type
Otto, 306
Advantages of scavenging, 380
Air, compression lines for, 40
— required in combustion of Dowson
gas, 365
— suction silencer for ' Stockport
Otto,' 318
— supply drawn through vaporiser in
oil engines, 471
— supply to Crossley oil engine, 434
— engine, Ericcson's, 24
— Joule's, 31
— Rankine on, 24
— Stirling's, 25
— Wenham's, 25
Air and gas mixtures :
— proportion of, 99, 100 101
— in Clerk engines, 193, 195
— Lenoir engines, 128, 252
— Otto engines, 173, 176
— Otto and Langen engines, 147
Allen's analysis of petroleum ether
and spirit, 393
American petroleum, composition of,
389
ATK
Analysis of coal gas :
Berlin, 271
Chemnitz, 271
Deutz, 172
Hoboken, 175
London, 271
Manchester, 109
Natural gas, 272
New York, 271
Analysis of Dowson gas, 363, 364
— of Lencauchez producer gas, 370
— of coal used in American gas pro-
ducer, 373
— of Scotch paraffin oil, 414
— of Russofine oil by Prof. Wilson,
425
Andrew & Co., J. E. H., Stockport
Otto engines, 318-324
low pressure starter, 352
Anthracite, consumption of, in gas
producer, 372, 373
Apparent indicated efficiency, 117
Apparatus for distilling oils, 402
— oil by air or steam, 405
Applications of petro'eum engines,
459
Atmospheric engines —
Barsanti and Matteucci, n
Brown's, 2
Gillies', 151
Otto and Langen, 136
Wenham's, 35
Atkinson's differential engine, 195
— cycle gas engine, 273-284
— engine : diagrams of linkage, 276
— Society of Arts test, 280
number of, in use, 283
— ' Utilit^ ' gas engine, 284-286
— Crossley Otto scavenging arrange-
ment, 313, 314
576
The Gas Engine
ATK
CLA
Atkinson's test of Crossley scavenging
engine, 318
Atkinson on increased compression,
379
Attempts at compounding gas en-
gines, 332
Available heat, definition of, 112
Average pressure less in oil engines,
465
— consumption of anthracite in pro-
ducers, 374
BARNETT'S compression engines, 5,
. 6, 9
— igniting cock, 7, 207
Barsanti and Matteucci engine, n
Barker's, T. B. , Otto engine, 324-329
— Otto engine tests of, at Saltley gas,
works, 329
Beau de Rochas on compression, 17
Berthelot, on calculation of tempera-
tures, 108
— explosion pressures, 106
wave, 114
time of explosion, 114
Berthelot and Vieille, explosion wave,
87, 88
Beechey, Mr., 'The Fawcett ' gas
engine, 293
Bellamy, Mr. A. R. , experiments on
increased compression, 321-322
Bellamy's experiments on increased
compression, 379
Bischoff engine, 132
Birmingham Corporation, tests of
Barker Otto engines, 329
Bousfield on stratification, 250
Boyle's law, 38
Brake, tests of :
— Brayton engine, 157, 159
— • Clerk engine, 191-4
— Otto engine, 172, 175, 180, 181
— Otto & Langen engine, 141
Brayton engine, 20, 32, 152
— tests of, 157, 159
— ignition, 217
— governor, 233
— petroleum pump, 156
Brayton oil engine, 407
Britannia oil engine, 449-453
Brown and Steward's trial of Otto
engine, 175
Brown's gas vacuum engine, 2
Broxbourne oil used in Crossley oil
engine, 438
Bunsen corroborates Davy's experi-
ments, 83
Bunsen on explosion pressure, 106
— velocity of flame propagation,.
84
highest temperature of combus-
tion, 93
— dissociation, 257
Bunsen burner, action of in varying
time of ignition, 328
— blue flame lamp, the Etna, 431-433
— from petroleum, 419
Burl's compound Otto engine, 332-
339
tests by Professor Jame-
son, 338
— test by Professor Rowden ,
338
— Otto engine, 339
— test of, 339
— high speed Otto engine, 340-342
CALORIFIC intensity, 90
— power, 90
Campbell gas engine, 286
— oil engine, 445-449
Capper, Professor, test of Hornsby
Ackroyd oil engine, 424-426
— Capitaine oil engine, 428
Capillary attraction, use of, in oil
engine lamp, 418
Charles's law, 38
Chemistry of petroleum and paraffin
oils, 388-406
Chemical reactions in gas producing,
356-359.
Classification of gas engines, 29
oil engines, 408-409
Clerk engine, 184
— tests of, 191-4
— igniting valves, 215, 217, 223
— governor, 233
— starting gear, first, 238
Clerk's explosion experiments, 95
Clerk, Crossley starting gear, 347-
348
— Lanchester starting gear, 348-349
— cycle, engines following the, 286
— heat-balance sheets in Hornsby
Ackrovd engine, 426
— Dugald tests of Crossley sca-
venging engine, 316
— Dugald tests of early and modern
Otto Crossley engines, 1881 and
1892, 308, 309
Clerk's (D.) tests of gas engine and
producer, 374
Clarke, Chapman & Co.'s oil
engine, 453-455
General Index
577
CLI
Clifton Rocks Railway ' Otto '
engine, 297-305
Clutch, Otto & Langen, 140
Combustion and explosion, 79
— heat evolved by, 89
— volume of products, 82
Combustion space ' Trent ' gas
engine, 288
— shape of, 290
— chamber, shape of, in Tangye
engine, 33O~332
— space, peculiar arrangement of in
Burl's high speed Otto engine,
34 1
of Dowson gas, heat evolved
by, 366
— chamber used as a vaporiser,
Hornsby Ackroyd oil engine, 420
and vaporiser of Robey oil
engine, 427
— Capitaine oil engine, 427-429
— chamber walls, temperature of,
468
Combining weights, 80
Compression engines —
Atkinson's, 197
Barnett's, 5, 6, 9
Brayton's, 20, 32, 152
Clerk's, 184
Million's, 16
Otto's, 172
Siemens', 18, 32
Stock port, 197
Tangye's (Robson's), 195
Compression, Barnett on, 5
— Beau de Rochas on, 17
— Jenkin on, 244
— Million on, 16
— Schmidt on, 17
— Siemens, proposed by, 17
— Witz on, 244
Compressions and gas consumptions
in early and modern Crossley Otto
engines, 317
— value of, to obtain economy, 318
— increase of, Mr. Bellamy's ex-
periments on, 321-322
— explosion obtained by Clerk-
Lanchester starter, 349
— space, importance of shape of,
3/8
— increase of, the cause of economy,
376-386
Comparative table of old and new
type, Crossley Otto engines, 310
— table of Crossley Otto gas
consumptions and compressions,
317
DAY
Comparison of ico-h.p. steam and
gas engine in cost of power, 354
— of gas for motive power and for
illumination, 355-56
Comparative values of hydrogen
and carbonic oxide for motive
power, 364
— table of theoretic and actual
efficiency, 377
— diagram of Crossley Otto engines
with different compression spaces,
378
— table of efficiency, 383
Comparison of oil engines of different
types, 473
Complete producer plants for 8o-h.p.
gas engine, 361-362
— combustion in oil engines,
necessity for, 388
Compound engine, the Burt Acme
engine, 332-339
— — principles advisable, 386
Condenser, excessive port surface
acting as a, 307
Conditions of gas engine economy,
34i
— of successful competition with
steam engine, 356
Constructional defects in Atkinson
Cycle engine, 283-284
Consumption of fuel in Dowson
producer, 371-374
Corliss type of gas engine by Messrs.
Robey, 342-344
Critical proportion of gas in mixture,
83
Crossley Otto engines, 297-318
power of, 297
— increase in economy of,
297
1892 engine governing gear, 301,
3°3
igniting valve and tube, 302,
305
engine, tests of, 308, 309
— engines, comparative table of
old and new types, 310
— scavenging engines, 309-317
engine, test by Atkinson,
318 -,
oil engine, 430-439
Crude petroleum, 388, 389
Cushion of inert gases, 247, 248
Cycles of action, 29-35
DAIMLER oil engine, 460-461
Davy, Sir H., on inflammability, 82
P P
578
The Gas Engine
DAY
DOW
Day gas engine, the, 290-293
Decomposing and vaporising oil,
methods of, 398-406
Decomposition of heavy oils, 403
Defects in construction, Atkinson
cycle engine, 283, 284
— of slide valves in gas engines, 304-
3°5
Design, gas engine, leading factors
in. 306-307
concerning ports and passages,
325-328
Destructive distillation, effect of in
gas production, 356
Deutz coal gas, 172
Dewar and Redwood's method of
distillation, 404
Diagrams, indicator :
Bischoff, 134
Brayton, 158, 160
Clerk, 192-5
Hugon, 132
Otto, 177, 179, 181
— Otto and Langen, 142, 147, 148,
150
— Lenoir, 124, 125,
— Simon, 164
— perfect theoretical :
- type i, 43
2, 47
3, 50, 52, 54,
i A, 54
— of Atkinson cycle engine linkage,
276
— indicator comparative Otto and
Atkinson ' Cycle' engines, 279
Atkinson cycle engine, Society
of Arts tests, 280, 281
— from Trent gas engine, 289
— from Day gas engine, 292
(Modern Crossley ' Otto'), 308
(Slide valve, Crossley ' Otto '),
3°9
— of valve setting in Crossley sca-
venging engine, 315
— indicator 4-n.h.p. Crossley sca-
venging engine, 316
— from ' Stockport Otto ' 321, 322
— Barker Otto engines, 329, 330
— Burt's compound Otto, 338
— Otto engine, 339
— high speed Otto, 342
Diagrammatic section, Clerk Lan-
chester starter, 349
Diagram, indicator, from Otto engine
using Dowson gas, 374
— comparative, Crossley Otto en-
gines, different compressions, 376
Diagram, theoretical, adiabatic and
isothermal expansion, 384
— indicator from Priestman oil
engine, 417
— of ignitions at low temperature.
422
Diagrammatic section, Clerk Crossley
starting gear, 348
Diagram indicator from Hornsby
Akroyd engine, 426
— from Robey oil engine, 428
from Clerk- Lanchester starter,
.350
Diagrammatic section, Lanchester
low-pressure starter, 350
Diagram, indicator from, Lanchester
low-pressure starter, 351
with coal and Dowson gas, 382
from Crossley oil engine, 438
— — from Fielding and Platt oil
engine, 444
from Campbell oil engine, 448
from Britannia oil engine, 452
from Weyman & Hitchcock's
oil engine, 458
from Wells Bros. ' oil engine, 460
Differential engine, 195
Difficulties of oil engine, 462-473
Dilution of mixtures, 83
Dimensions of 6-n.h.p. Atkinson
Cycle engine, 277
— of 4-n.h.p. Atkinson Cycle engine,
278
— of Burt's compound Otto engine,
336
Dissociation, Deville on, 92, 93
— Bunsen's theory of, 257
— definition of, 92
— Groves on, 92
— Thurstoh on, 178
Distillation of solid paraffin with
steam, 400
— of oils, experiments in, 400-406
Distilling oil by air or steam, appa-
ratus for, 405
Dowson plant used to operate 400-
h.p. engine, 324
— gas used in Wells Bros. ' scavenging
engine, 344, 345
— producer, fuel for, 354
— producer, the, 359-376
analysis cf, 363-364
— heat evolved by combustion of,
366
producer, consump ion of fuel,
37i
- producer and Otto engine, test
by D. Clerk, 374
General Index
579
DRA
Drake's engine, 10
— ignition, 10
Dulong and Petit's law, 90
EARLY oil engines, 407
Economy, the result of increased com-
pression, 376-386
— due to scavenging, 379
Efficiency, definition of, 37
— of perfect heat engine, 39
— of imperfect heat engine, 41
— formulae, 56, 57
— apparent indicated, 117
— actual indicated, 117
— of gas in explosive mixtures, 112
— of Atkinson cycle engines, 283
— mechanical, of ' Trent ' gas
engine, 289
— indicated, of ' Fawcett ' gas engine,
290
— mechanical, of old and new type
Crossley ' Otto' engines, 310
— of Dowson gas producer, 367
— Lencauchez gas producer, 370
— in ' Otto ' engines, gradual increase
in, 375-376
— absolute, increase of, 384
— comparative, of oil and gas engine,
462
Efficiencies, table of, 68
— of Brayton engine, 162
— of Clerk engine, 192
— of Lenoir engine, 128
— of Otto engine, 172, 176
— of Otto and Langen engine, 141
— comparative table of, 383
— yet possible in gas engines, 386
Electrical ignition, 203, 205
— in Priestman engine, 411
— objectionable, 462
— lighting, engines for, good govern-
ing method in, 346
Equivalent, mechanical, of heat, 36
Ericcson engine, fuel used, 26
Erroneous heat values in oil engine
tests, 425
Ether, petroleum, and spirit, 393
Etna lamp type used in oil engines,
431-433
Evaporation of water by air, 399
— of petroleum by air, 400
Exhaust gases, temperature of
Lenoir, 122
— velocity of, in old type Otto,
306
velocity of,, in new type Otto,
FLA
Exhaust pipe, oscillations or waves
of pressure in, 313
— valve, arrangement of in Robey's
' Otto ' engine, 342
— heating vaporiser in Priestman
engine, 412
— valve closed during governing,
4*7
— valve held open when governing,
448
— gases heating air supply in oil
engine, 453
Expansion of gases bv heat, 38
— gas engine, 332-339
— a source of further economy, 386
Experiments in increased compres-
sion, Bellamy's, 321-322
— in petroleum and shale oils,
Robinson, 397
— in distillation of oils, 400-406
— with ignitions at low temperatures,
422-423
Explosion, 95, 115
— chemical reactions of, 81, 82
— Clerk's apparatus, 95, 90
— combustion and, 79
— observed and calculated pressures,
104, 106
— proportion of heat evolved by,
JI3
— premature avoided by scavenging,
380
Explosive mixtures, true, 79-82
— efficiencies of gas in, 112
— curves of cooling, 97, 98
— inflammability of, 83
— pressures produced by, 99-101
— flame propagation in, 84-95
— temperature produced by, 107-
iii
— volumes of products, 82
External vaporiser oil engines, 429-
459
FAWCETT gas engine, the. 293-296
Fielding .& Plait's 'Otto' engines,
346
— starting gear, 353
— oil engine, 442-445
Flame propagation :
— Berthelot and Vieille on, 87, 88
— Runsen on, 84
— Mallard and Le Chatelier on,
85-87
Flame, temperature of, 93, 94, 108,
109, no, in
— theoretical temperature of, 91
P P 2
The Gas Engine
FLA
Flame, temperature of, in Lenoir
engine, 126
— Brayton engine, 161
— Otto and Langen engine,
146-149
Otto engine, 177, 179
— starting gear, the Clerk Crossley,
347-348
Flashing point of British sold lamp
oils, 394, 396
Foster, Professor, analysis of Dowson
gas, 363
Free piston engines :
Barsanti's and Matteucci, n
Gillies', 151
Otto and Langen, 10, 136
Type i A, 66
Wenham, 35
French analysis of Dowson gas, 364
Friction of Brayton engine, 15
Otto engine, 174
Furnace engine, Cayley, 25
Wenham, 25
— loss in cylinder, 112
Future of gas engine, 260
Fuel for Dowson gas producer, 354
— consumption of gas engines with
producer gas, 371
GARRET'S governor (Clerk engine),
234
Gas, coal analysis of :
Berlin, 271
Chemnitz, 271
Deutz, 172
Hoboken, 175
London, 271
Manchester, 109
Natural gas, 272
New York, 271
Gas and air mixtures, explosions of,
99, 100, 101
— best proportions of, 101-104
Gas, consumption of, by Bischoff
engine, 134
— Atkinson cycle engine, 283
— Brayton engine, 158
— Clerk engine, 191-194
— 9-n.h.p. Crossley Otto 1892,
308
— 6-n.h.p. Crossley Otto 1881, 309
— 4-n.h.p. Crossley scavenging
engine, 316
— ' Fawcett ' engine, 296
— Hugon engine, 132
Lenoir engine, 124, 252
Otto engine, 172, 175, 180, 183
GAS
Gas, consumption of, by Otto and
Langen, 141
— ' Trent ' engine, 289
Gas consumptions, comparative table
of, in Crossley engines, 317
— Barker Otto engines, 329, 330
— Burt's compound Otto, 338
— Burt's Otto engine, 339
— Crossley Otto engines, decrease
in. 375
— Stockport Otto engine, 321-322
- Tangye's Otto engines, 332
— Wells Bros. ' Otto engine, 346
— efficiency of in explosive mixtures,
112, 113
— for motive power and illuminating
gas, 355
Gas engine, Atkinson ' Cycle, ' 278-
284
— Atkinson ' UtiliteY 284-286
- The ' Campbell,' 286
— Otto Crossley scavenging, 309-
3*7
— The ' Day, '290, 293
— The ' Fawcett,' 293-296
- The ' Midland,' 287
- The ' Trent,' 287-290
- The ' Stockport Otto,' 318-324
The Barker Otto engine, 324-
329
— Otto Tangye, 329-332
— The Burt Compound Otto
engine, 332-339
— Burt's high speed Otto, 340, 342
— Robey's Otto, 342-344
— Wells Bros.' Otto, 344-346
— Fielding and Platt's Otto engine,
346
giving impulse every revolution,
286
— design, leading factors in, 306-
3°7
comparative table of old and
new type Crossley Otto, 310
the largest manufactured, 322-
324
— working with producer gas,
precautions required, 366
— and producer, consumption of
fuel, 371, 373
Gas, Dowson, volume of air required
for combustion, 365
heat evolved by combustion of,
366
Gas production, chemical reactions
in, 356-359
Gas producers, conditions of success,
355
General Index
58i
GAS
IGN
Gas producer, the Lencauchez, 367-
370
Gas, Lencauchez producer, analysis
of, 370
Gas producers, Dowson, 359-367
— other makers of, 370
— Dowson, fuel for, 354
Gas producer plant for 80 h. p. engine,
361-362
— Dowson, analysis of, 363-364
Gay-Lussac's laws, 82
Gear wheels, disadvantages of, 339
Gillies' engine, 151
Glycerine bath for oil engine pump,
429
Governors of Bischoff engine, 226
— Brayton and Lenoir, 233
— Clerk, 234
— Lenoir and Hugon, 226
— Otto, 230. 231, 232
— Otto and Langen, 227
— Tangye (Pinkney), 235
Governing in Crossley oil engine, 433
- Tangye oil engine, 439-440
— Campbell oil engine, 447-448
— Britannia oil engine, 450
— Clarke Chapman's oil engine, 455
— Wells Bros.' oil engine, 457
— difficulties in Priestman engine,
466
— Samuelson engine, 467
— Hornsby oil engine, 469
Governor gear of Crossley ' Otto '
1892 engine, 301-303
Governing arrangements in Fielding
and Platt's Otto, 346
Governor gear in Priestman engine,
414
Governing arrangements in Samuel-
son engine, 416
Griffin patent Samuelson oil engine,
416-420
Guilford, Mr. F. L., tests of 'Trent '
engine, 289
HAUTEFETJILLE'S, Abbe", engine, i
Heat, available definition of, 112
— table of, 113
— balance sheets of Otto engine,
172, 176
— engines perfect, 39
— imperfect, 41
— evolved by combustion, 88, 89
— balance sheet in Society of Arts
test of Atkinson cycle engine, 283
— evolved by combustion of Dowson
gas, 366
Heat, balance-sheet of Hornsby
Akroyd engine, 425, 426
— mechanical equivalent of, 36
— losses in gas engine, 72
— lost through surfaces in Otto, 172,
176
— of compression, 40, 270
— specific of gases, 90
— constant volume, 89, 90
— pressure, 89, 90
— unit, 89
Heating value of Openshaw gas, 375
— of vaporiser charge in Crossley
Otto oil engine, 430
— air supply in oil engine, advantage
of, 442
— in Britannia oil engine, 450
Heavy oils, decomposition of, 403
High pressure starter, Clerk Lan-
chester, 349
— speed utto engine, Burt's, 339 —
342
Hirn's experiments in explosion, 104,
IOS
— theory of limit by cooling, 257
Hoboken, coal gas, 175
Hopkinson, Dr. John, Judge in
Society of Arts tests, 279
Hornsby Akroyd oil engine, 420-426
Hot air engines, Ericcson's, 25
Joule's, 25
— Rankine on, 24
Stirling's, 25
— Wenham's, 25
Hugon's engine, 20, 129
— igniting valve, 209
Huyghens' gunpowder engine, i
Hydrogen, 80, 82
— heat evolved by, 89
— mixtures, 84, 86, 87
Hydrogen and carbonic oxide, com-
parative values of, for motive power,
364
IGNITING arrangements, 20?
— chemical, 225
— electrical, 203-207
— flame, 207-221
— incandescence, 222-224
Ignition, varying of, in Barker Otto
engine, 328
— arrangement in Samuelson oil
engine, 418
— of oil vapour and air at low tem-
perature, 422
gas and air at oil temperature
422-423
582
The Gas Engine
IGN
LEN
Ignition lamp, type in use in low
engines, 43I~433
— in Crossley oil engine, 435
— tube and vaporiser combined in
oil engine, 461
— in Daimler engine, 461
Illuminating gas and gas for motive
power, 355
Imperfect mixture in Hornsby oil
engine, 418
Importance of shape of compression
space, 378
Improvements desirable in oil en-
gines, 472
Impulse - every - revolution engines,
future of, 272
Impulse-every-revolution engines, 286
Impulses not cut out in Fielding and
Plan's engines, 346
Imray on stratification, 250, 254
Incandescent igniter-tube and valve
for Otto Crossley 1892 engine, 303,
3°5
Incandescent igniter-tube and valve
for ' Stockport Otto,' 319, 320
— used in starting gear, 352
Increase in economy value of com-
pression, 318
— in initial pressures, 385
Increased compression, cause of
economy, 376-386
Atkinson on, 379
— • economy still possible, 381-386
>le, 381-
in Cros
— limits of, 385
till poi
Indicated efficiencies in Crossley oil
engines, 376
Indicator diagrams, theoretical, 43,
47. 50- 52. 54
Comparative Otto and Atkin-
son cycle engines, 279
(Society of Arts Atkinson cycle
engine), 280, 281
('Trent ' gas engine), 289
— — (' Day ' gas engine), 292
(Modern Otto Crossley engine),
308
(Slide valve Otto Crossley
engine), 309
— 4-n.h.p. Crossley scavenging
engine, 316
— from 'Stockport Otto,' 321,
322
Barker Otto engine, 329, 330
Burl's compound Otto, 338
— high speed Otto engine, 342
— Otto engine, 339
— from Clerk-Lanchester starter,
35°
Indicator diagrams from Lanchester
low-pressure starter, 351
— from Otto engine using pro-
ducer gas, 374
- — from engine with ordinary and
Dowson gas, 382
— from Priestman oil engine, 417
— of ignitions at low temperatures,
422
from Hornsby Akroyd oil en-
gine, 426
— from Robey oil engine, 428
from Crossley oil engine, 438
from Fielding and Platt oil
engine, <\\\
— from Campbell oil engine, 448
- — from Britannia oil engine, 452
— from Weyman and Hitchcock
oil engine, 458
— Wells Bros.' oil engine, 460
Inert gas, cushion of, 247, 248
— diluent, 246, 247
Inflammability, 82
Inflammation, definition of, 99
Isothermal line, 40
JACKET, water, use of, 27
Jameson, Professor, tests of Burt's
compound Otto, 338
Jenkin, Prof. Fleeming, on compres-
sion, 244
— on future of gas engine, 268
Joule, Dr., hot air engine of, 31
KENNEDY, A. B. W., Judge in
Society of Arts tests, 279
LAMP to heat ignition tube in
Samuelson oil engine, 419
— type to use in oil engines, the
Etna, 431-433
— for Crossley oil engine, 436
— Britannia oil engine, 451
Lanchester, F. W., designer of
Barker Otto engine, 329
— and D. Clerk self-starter, 349
— low-pressure starter, 349-352
Langen's, Otto and, engine, 10, 136
Largest engine manufactured, Stock-
port Otto, 322-324
Launches, oil engines suitable for,
459
Lebon's engine, 5
Legal restrictions upon light oils, 388
Lencauchez gas producer, 367-370
General Index
583
LEN
Lencauchez producer gas, analysis
of, 370 .
Lenoir engine, 13, 15, 30, 118
— electrical ignition, 203
Light spring indicator diagrams
Crossley Otto engines, 308-309
— diagram Crossley scavenging
engine, 316
- Stockport Otto engine,
321
Limitation of charge in oil engine
owing to heating, 465
Limits of increased compression, 385
— of increase in gas engine efficiencies,
383
— of heat evolution, 257-9
London coal gas, 271
Losses in gas engines, 72, 78
Low pressure starter, Lanchester,
Lowest flashing point of oils, 396
Lubrication, 235-238
MALLARD and Le Chatelier's experi-
ments, 85-87
— theory of limit, 258
Maximum compressions possible, 385
Mean pressure in gas engine with
producer gas, 371
Mean pressures less in oil engines, 465
Members of the Olefine series, 391
Methods still open to obtain increased
economy, 381-386
Mechanical efficiency, Otto, 174
Midland gas engine, The, 287
Miller, Mr. T. L. , tests of ' Fawcett '
gas engine, 296
Million on compression, 17
— gas engine, 17
Mixtures, true explosive, 79-82
— best for non-compression engine,
101
— dilute, 83
Mixing valve, Clerk, 187
— Lenoir, 121
— Otto, 170
Morrison, Mr. J. W., tests of Barker
Otto engine, 329
Motive power, gas necessary for, 355
NAPHTHENE isolated from Russian
petroleum, 392*
Neutral gases, cushion of, 247, 248
Non-compression engines —
Barsanti and Matteucci's, n
Bischoff1 s, 132
OIL
Non-compression engines —
Gillies', 151
Hugon's, 20, 129
Lenoir's, 118
Otto and Langen's, 136
Street's, i
Wenham's, 35
Wright's, 3
Non-conducting material in Capitaine
vaporiser, 429
Norton, Prof., on Ericcson, 26
Notable quantity, 246
OILERS Otto's, 236
— Clerk's, 238
Oils, American petroleum, compo-
sition of, 389
— consumption of Priestman engine,
414-416
of Hornsby Akroyd oil engine,
424-426
of Crossley oil engine, 437-439
of Fielding and Piatt oil engine,
4-14
in Campbell oil engine, 448
— in Britannia oil engine, 452
— in Wells Bros.' oil engine, 458
— in Weyman and Hitchcock's
engine, 456
— distillation of, experiments in, 400-
406
— Pennsylvania petroleum, compo-
sition of, 390
— petroleum principally used, 388
— petroleum and paraffin, sold in
Britain, 394
— flashing point of, 394
— petroleum and shale oils, Robin-
son's table of, 397
— engines, Messrs. Wells Bros., 456-
459 .
— engine, the Hock, 407
the Bray ton, 407
— the Spiel, 408
— the Samuelson, 416-420
— the Hornsby Akroyd, 420-426
— the Robey, 427
— the Capitaine, 427-429
the Crossley Otto, 430-439
— the Tangye, 439-442
— Fielding and Platt's, 442-445
— the Campbell, 445-449
— the Britannia, 449-453
— Clarke, Chapman & Co.'s, 453-
455
Weyman and Hitchcock's, 455-
456
584
The Gas Engine
OIL
PET
Oil engine, the Daimler, 460-461
— difficulties of, 462-473
— complete combustion necessary,
388
— oil used in early, 388
— early forms of, 407
in which the oil is sprayed first,
409-420
— method of spray diffusion, 410
— the Priestman, 410-416
— pump used in Capitaine oil
engine, 429, 430
— with external vaporisers, 429-
459 .
— engine lamp, type generally in use,
431-433.
— supply in Crossley oil engine, 435
— in Tangye oil engine, 441
— in Campbell oil engine, 446
— feed and governing in Britannia
oil engine, 450
— supply in Wells Bros.' oil engine,
458
— engines of different types com-
pared, 473
— engine improvements, 473
Olefine series, members of, 391
Otto's engine, 136
— governor, 228, 232
— igniting valve, 242
— starting gear, 242
— tests of, 172, 175, 180, 181
Otto's theory, 245
Otto and Langen's clutch, 136
— engine, 136
— M. Tresca on, 145
— patent, expiration, 271
— Crossley engines, increase in eco-
nomy of, 297
— power of, 297
— engines made by Messrs. Crossley
Bros. , 297-318
— Crossley engine 1892 : igniting
valve and tube, 302, 305
1892 : governing gear, 301-
303
— tests of, 308-389
— scavenging engine, 309-317
engines, comparative table of
old and new types, 310
— scavenging engine test by Atkin-
son, 318
— engines, comparative diagram
of, 378
oil engine, 430-439
cycle engines, leading makers
of, 272
— Stockport engines, 318-324
Otto Stockport engines, tests by
Bellamy, 321, 322
— engine, 4oo-h.p. largest made,
322, 324
- Tangye engine, 329-332
— engine, Burl's patents, 339
— engines by Messrs. Robey, 342-344
— high speed engine, Burl's, 340-342
— engines by Messrs. Fielding and
Platt, 346
— engines by Messrs. Wells Bros. ,
344-346
— Barker engine, 324-329
— tesls at Saltley gas works, 329
PACKED charge, 247
Paraffin oil, Scolch analysis of, 414
Papin's experimenls, i
Pelroleum engine, Brayton's, 152
early forms of, 407
the Hock, 407
the Bray ton, 407
the Spiel, 408
— — in which the oil is first sprayed,
409-420
— method of spray diffusion, 410
— the Samuelson, 416-420
- spraying device in Samuelson
engine, 418
— vaporiser in Samuelson oil engine,
419
— engine, ignition lamp in Samuelson,
419
— engines, the Hornsby Akroyd,
420-426
vaporiser and cylinder, Hornsby
Akroyd, 421
— the Robey, 427
— the Capitaine, 427-429
— with exlernal vaporisers, 429-
459
— the Crossley Otlo, 430-439
— engine lamp, type in use, 431-433
— the Tangye, 439~442
— Fielding and Plait's, 442-445
— the Campbell, 445-449
— the Britannia, 449-453
— Clarke, Chapman & Co. , 453-
455
Weymanand Hilchcock's, 455-
456
— Wells Bros.', 4^56-459
— The Daimler, 460-461
— of different types compared,
473
— and paraffin oils, chemistry of,
388-406
General Index
585
PET
Petroleums principally used, 388
— crude, 388, 389
— American, composition of, 389
Pennsylvania petroleum, composition
of, 390
Petroleum, Russian, naphthenes in,
392
— ether and spirit, 393
— and shale oils, British, Professor
Robinson's experiments in, 397
— and paraffin burning oils sold in
Britain, 394-398
— flashing point of, 394
— vaporised with air, 400
- oils, distilling by air or steam,
4°5
- oils, experiments in distillation of,
400-406
— heavy oil, decomposition of, 403
Pinkney's governor, 156
— patent Tangye oil engine, 439
Piston velocity in Lenoir engine,
i4S.
in Otto engine, 172, 175
— in Otto and Langen engine,
144
- speed old and new type Otto
Crossley engines, 310
— valve in Fawcett gas engine, 295
— valves in Burt's Otto engines, 339
340
Ports, action of excessive surface in,
307
Ports and passages, design of, 325,
328
Possible efficiencies in gas engines,
•;86
Priestman oil engine vaporiser and
cylinder, 411
— 410-416
— spraying jet and air valve,
412
— governor gear, 414
— tests of by Unwin, 414-416
Premature ignitions, cause of, 306
— explosions avoided by scavenging,
380
Pressure, effect of heating oil under,
403
— advantage of, in vapour jet, 437
— and temperature, 38, 107
— produced by explosion, 99-101
— if no loss existed, 104-105
Products of combustion, 82, 109
— proportion in Hugon engine,
131 ' T
in Lenoir engine, 131
in Otto engine, 173
ROB
Products of combustion totally ex-
pelled in Atkinson Cycle engine, 283
Producer gas, chemical reactions in
making, 356-359
— Dowson gas, 359-367
— Lencauchez gas, 367-370
— Dowson gas, consumption of fuel,
371
- Taylor's gas, test with loo-h.p.
engine, 373
Pump for oil used in Capitaine oil
engine, 429
— and oil supply in Crossley engine,
435
Pure mixture obtained by scavenging,
3H
RANKINE on air engine, 24
— available heat, 112
— • science of thermodynamics,
36
Ratio of air to gas, in explosive mix-
tures, 99-101
in Clerk's engine, 193, 195
— in Lenoir's engine, 128
— in Otto's engine, 173, 176
— - — in Otto and Langen 's
engine, 14
Ratio of compression space :
in Clerk's engine, 192
• in Million's engine, 17
— in Otto's engine, 172, 175
— of air to gas. Atkinson engine,
Society of Arts tests, 282
— of specific heats. Erroneous
assumption by Society of Arts in
their tests, 281-282
Reactions, chemical, in gas produc-
ing, 356-359
Reduction in gas consumption due
to increased compression, 318
Redwood and Dewar's method of oil
distillation, 404
Red-hot surfaces in vaporisers a
mistake, 406
Relative cost of power, steam and
gas engine, 354
Reservoir, use of, in starting gear,
353
Richards' analysis of Lencauchez gas,
370
Richardson and Norris, the Robey oil
engine, 427
Robson's engine, 195
Robinson, Professor, experiments on
British sold petroleum and shale
oils, 397
586
The Gas Engine
ROB
TEM
Robey's Otto engine, 342-344
Robey oil engine, 427
Root's patent oil engine (the
Britannia), 449-453
Rowden, Professor W. J., on the
Burt compound engine, 333
— test of Burt's compound Otto,
338
Royal daylight oil, distillation of,
401
Russoline oil analysis by Wilson,
425
SALTLEY gas works test of Barker
Otto engine, 329
Samuelson oil engine, 416-420
Scavenging engine, Crossley Otto
engine, 309-317
— advantages of, 380
— arrangements in Wells Bros.' Otto,
344
— economy due to, 379
Scotch paraffin oil, analysis of,
414
Schmidt on compression, 16
Schottler on stratification, 256
— tests of Otto engine, 180
Self-starting gear, necessity for,
347
Shale and petroleum oils, Robinson's
table of, 397
Silencer for Stockport ' Otto ' air
suction, 318
Simon's ' Trent ' gas engine,^ 287-
290
Simplest gas engine starter, 350
Simon's steam gas engine, 32, 163
Slow combustion, Bousfield on, 250
— Imray on, 250
— Otto on, 246
— Slaby on, 247-9
Slide valves, defects of, 304-305
Spangler, Mr. H. W. , test of xoo-h.p.
engine and gas producer, 373
Specific heats, ratio of. Erroneous
assumption of Society of Arts
Judges, 281-282
Specific heat of gases, 90
Spiel petroleum engine, 408
Spray diffuser, type of in use in oil
engines, 410
Spray lamp in Samuelson engine,
419
Spraying jet and air valve, Pnestman,
412
— device in Samuelson engine, 418
— method in oil engines, 464
Starting gear, Clerk's, 239
— Otto's, 242
— for Stockport ' Otto,' 320
- — the Clerk Crossley, 347-348
— the Clerk Lanchester, 348-349
— Lanchester low-pressure, 349-
352
— on Stockport Otto engines,
352
Tangye Otto engines, 352
- Fielding & Platt's Otto
engines, 353
— Samuelson oil engine, 420
— Hornsby Akroyd engine, 420,
423
— the Capitaine oil engine, 428
— the Etna oil engine lamp, 433
— the Tangye oil engine, 439
— Fielding & Piatt's oil engine, 443
— lamp in Britannia oil engine, 451
Stockport Otto engines, tests by Mr.
Bellamy, 321, 322
— 318-324
4co-h.p. engine, largest made,
322-324
Stockport engine, 197
Stratification, Bousfield on, 250
— experiments in support of, 249,
250
— • fallacy of, 254, 255, 256
— Lenoir on, 16
— Otto on, 246
— Schottler on, 256
— Slaby on, 247, 248
Street's gas engine pump, i
TABLE of efficiencies, 68
Tandem gas engine, Stockport Otto,
400-h.p., 322-324
— engine, Burt's high-speed Otto,
340
Messrs. Fielding & Platt's, 346
Tangye's Otto engine, 329-332
— starting gear, 352
— oil engine, 439-442
— engine (Robson's), 195
Tar in producer gas, 370
Taylor's gas producer, tests of, 373
Temperature of combustion in
Bray ton engine, 161
exhaust in Lenoir' s engine, 122
in Otto engine, 173, 176
Temperatures of explosion, 107-111
in Lenoir's engine, 125, 126
in Otto and Langen engine,
146, 149
in Otto engine, 177, 179
General Index
587
TEM
UNW
Temperatures of air supply in Priest-
man oil engine, 464
— walls of combustion chamber in
oil engine, 468
Tests of 4-n.h.p. , Atkinson Cycle
engine, 278
modern Crossley ' Otto ' engine
1892, 308
— slide valve Otto engine 1881,
309
Crossley Otto scavenging
engine by D. Clerk, 316
— Crossley Otto engine by Society
of Arts, 317
scavenging engine by Atkin-
son, 318
— Stockport Otto engine with
increased compression, 321, 322
Barker Otto engine at Sallley
gas works, 329, 330
— Tangye's Otto engine, 35-
n.h.p., 332
Burl's compound Otto by
Jameson, 338
— Rowden, 338
— — a 6-b.h.p. Wells Bros.' Otto
engine, 346
Dowson producer and 6o-h.p. v
Otto engine, 371
— and loo-h.p. complex
engine, 373
— ico-h.p. Otto and gas pro-
ducer, 373
• Otto engine and Dowson pro-
ducer by D. Clerk, 374
Testing the flashing point of oils,
394-395
Tests and oil consumption in Priest-
man oil engine, 414-416
of Hornsby Akroyd oil
engine, 424-426
— of Capitaine oil engine, 428
— and oil consumption of Crossley
oil engine, 437-439
— of Fielding & Plait's oil
engine, 444
in Campbell oil engine,
448 ,
Britannia oil engine, 452
in Weyman & Hitchcock
engine, 456
— in Wells Bros.' oil engine,
458
Theoretic efficiencies, 68
Theories of action in cylinder, 243
Theoretical riagram, adiabalic and
isolhermal lines, 384
Theory of vaporising oil, 398-406
Thermodynamics of Ihe gas engine,
36
1 hermal units in Russoline and Royal
daylight oils, 416
Throtlling in entering gases, 305
Thurston's experiments on Otto
engine, 175
— on dissociation, 178
Time taken to start Hornsby Akroyd
oil engine, 424
— Capitaine oil engine, 428
— Crossley oil engine, 437
Fielding & Platt's oil
engine, 444
— Britannia oil engine, 453
Timing valve, absence of, in Barker
Otlo, 328
Tower, Mr. Beauchamp, Judge in
Society of Arts tests, 279
Tresca's experiments in Lenoir
engine, 123
— in Hugon engine, 132
— Olto and Langen engine, 141
— theories of Otto and Langen
engine, 145
Trent gas engine, the, 287-290
Trunk piston of two diameters, 287
Type, first description of perfecl cycle,
29
— second descriplion of perfect cycle,
3°
— third description of perfect cycle,
32
— i A, description of perfect cycle,
34
— I :'
Lenoir engine, 118
Hugon engine, 129
BischofF engine, 132
— 2 :
Brayton petroleum engine, 152
Simon engine, 163
Atkinson engine, 199
Clerk engine, 184
Otto engine, 166
Stockporl engine, 197
Tangye engine, 197
— i A:
Gillies' engine, 151
Olto and Langen engine, 136
Types of oil engines, 408-409
— of vaporiser deptndenl on oil,
398
UNWIN, Professor, lesls of Alkinson
' Cycle ' engine, 278-279
588
The Gas Engine
UNW
WRI
Unwin, Professor, tests of Priestman
oilengine, 414-416
' Utilite" ' Atkinson gas engine, 284-
286
VACUUM gas engine. 2
— partial, induced in exhaust pipe,
3J3
Valve-gearing ' Trent ' gas engine,
288
of ' Stockport Otto ' engine,
319-320
of 400 h.p. 'Stockport Otto,'
324-325
and arrangements of Barker
'Otto/ 326-327
in Burt's high speed Otto en-
gine, 340-341
Valveless gas engine, ' The Day,'
290
Valve setting in Crossley Otto sca-
venging engine, 315
Vaporiser surfaces should not be
red hot, 406
— and cylinder of Priestman oil
engine, 411
— in Samuelson oil engine, 419
— and cylinder Hornsby Akroyd
engine, 421
— and combustion chamber of
Robey oil engine, 427
— Capitaine oil engine,
4.29
— in Crossley oil engine, 434
— in Tangye oil engine, 440
— and ignition tube combined in
Fielding & Platt oil engine, 442
— in Campbell oil engine, 445
— and ignition in Britannia oil
engine, 449
Vaporiser, type of, dependent on
oil, 398
Vaporising arrangements in Clarke &
Chapman's oil engine, 453
— Weyman & Hitchcock en-
gine. 455
— in external vessel, method of, 470
— light oils, 387
Vaporising petroleum with air, 400
— and decomposing methods of,
398-406
Vapour tension of water, 398-399
Varying ignition in Barker Otto
without timing valve, 328
Velocity of flame propagation, 85
entering mixture in early ~Otto-
Crossley engines, 305
exhaust gases in neW type
Otto, 306
— old type Otto, 306
entering mixture in modern
Otto Crossley engine, 306
Volumes and relative weights of
gases, 8 1
— of Deutz coal gas,
172
— of Hoboken coal gas,
176
Volume of air required in combus-
tion of Dowson gas, 365
Volatile liquids produced from*
petroleum, 393
WALLS of combustion chamber,
temperature of, 468
Water jacket, use of, 27
— evaporated by air, 399
— gas for gas engines, 370
— jacket heat lost in Atkinson's
' Cycle ' engine, 278
— Priestman oil engine,
4i5
— vapour tension, 398, 399
Wave explosion, 114
Waves of pressure or oscillations in
exhaust pipe, 313
Wedding on dissociation, 183
Weights and volume, relative, of
gases, 8 1
— molecular, of gases, 81, 82
Wells Bros.' Otto engine, 344-346
— oil engine, 459
Weyman & Hitchcock's oil engine,
455-456
Wenham s engines, 25, 35
Whole air charge drawn through
vaporiser in oil engines, 471
Wiltz on compression, 244
— Professor A. , test of a ico-h. p.
engine and gas producer, 373
Wilson, Mr. C. J., analysis of Scotch
paraffin oil, 414
— analysis of Russoline oil, 425
Wright's engine, 3
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